Anna had disposed his army in and around Mexico City, strongly fortifying the many natural obstacles that lay in the way of the Americans.

Scott first encountered stiff resistance at Contreras (18-20 August 1847) where the Mexicans were finally put to flight after suffering an estimated 700 casualties and the loss of 800 prisoners. Santa Anna promptly made another stand on Churubusco (20 August 1847) where he suffered a disastrous defeat in which his total losses for the day-killed, wounded, and especially deserters were probably as high as 10,000. Scott estimated the Mexican losses at 4,297 killed and wounded, and he took 2,637 prisoners. Of 8.497 Americans engaged in the almost continuous battles of Contreras and Churubusco, 131 were killed, 865 wounded, and about 40 missing.

Scott proposed an armistice to discuss peace terms. Santa Anna quickly agreed; but after two weeks of fruitless negotiation it became apparent that the Mexicans were using the armistice merely for a breathing spell. On 6 September Scott broke off the discussions and prepared to assault the capital. To do so it was necessary to take the citadel of Chapultepec, a massive stone fortress on top of a hill about a mile outside the city proper. Defending Mexico City were from 18.000 to 20,000 troops, and the Mexicans were confident of victory, since it was known that Scott had barely 8,000 men and was far from his base of supply.

On 8 September 1847 the Americans launched an assault on Molino del Rey, the most important outwork of Chapultepec. It was taken after a bloody fight, in which the Mexicans suffered an estimated 2,000 casualties and lost 700 as prisoners, while perhaps as many as 2,000 deserted. The small American force had sustained comparatively serious losses-124 killed and 582 wounded-but

they doggedly continued their attack on Chapultepec, which finally fell on 13 September 1847. American losses were 138 killed and 673 wounded during the siege of the fortress. Mexican losses in killed, wounded, and captured totaled about 1.800. The fall of the citadel brought Mexican resistance practically to an end. Authorities in Mexico City sent out a white flag on 14 September 1847. Santa Anna abdicated the Presidency, and the last remnant of his army, about 1,500 volunteers, was completely defeated a few days later while attempting to capture an American supply train.

CONCLUSION OF THE WAR. For two months after Chapultepec the only responsible government in Mexico was the American military government under Scott. Eventually the Mexicans set up a government with Manuel de la Pena y Pena as acting executive, and four peace commissioners were appointed J. B. Couto, L. G. Cuevas, Miguel Atristain, and Manuel Rincón (who did not serve)-with whom Nicholas P. Trist negotiated peace terms. In the Treaty of Guadalupe Hidalgo, signed on 2 February 1848, Mexico recognized the Rio Grande as the boundary of Texas and ceded New Mexico (the present States of Arizona, New Mexico, Utah, and Nevada, and parts of Wyoming and Colorado) and "Upper California" (the present State of California) to the United States. In return the United States agreed to pay Mexico fifteen million dollars and to assume the unpaid claims against that country. President Polk, wisely resisting public demands that the whole of Mexico be annexed, sent the treaty to the Senate, which approved ratification, after a bitter debate, on 10 March 1848. The Mexican Congress approved ratification in May, and on 1 August 1848 the last American soldier departed Mexican soil.

CAUSES OF THE WAR. From the beginning of the colonial period there were marked differences between the northern and southern sections of what became the United States. After the

American Revolution these sectional differences did not at first seriously affect the unity of the nation; but eventually the slavery issue emerged as an emotional focal point for bitter

disagreements in political, social, and economic fields. Failure to find reasonable and acceptable solutions to the various problems led to civil war.

Southern dissidence reached a climax with the election of Abraham Lincoln as President in November 1860. This was a triumph for the new Republican Party, which opposed the further extension of slavery and favored economic policies opposed by the South. In the month following the elections, South Carolina passed an ordinance of secession, and by 1 February 1861 similar action had been taken by Mississippi, Florida, Alabama, Georgia, Louisiana, and Texas. In most cases the seceded States issued statements in which they defended slavery on moral and economic grounds, declared that acts sponsored by antislavery forces had violated the "constitutional compact" and had thereby released the slave States from their obligations, and asserted the right of self-determination. These official statements of causes were, in effect, declarations of independence; and the country went to war principally to settle the basic issue of whether or not the Federal Government had the right to compel a State to remain in the Union.

On 9 January 1861 South Carolinians fired on an armed steamship, the Star of the West, when it made an unsuccessful attempt to deliver supplies and reinforcements to Fort Sumter at Charleston. President Buchanan refused to make an issue either of this act of war or of other acts of defiance that occurred during the remainder of his term. In February 1861 a provisional government, calling itself the Confederate States of America, was established at Montgomery, Alabama, with Jefferson Davis as President. The seceded States seized Federal property within their borders (except Fort Sumter in Charleston Harbor and Fort Pickens at Pensacola) and in February Davis called for 100,000 volunteers to serve the Confederacy for 12 months. Thus, when Lincoln became President on 4 March 1861, he found himself confronted with a fullfledged rebellion.

Anxious to avert war but determined to maintain the Union, Lincoln's first decisive step was to notify the Gover

nor of South Carolina that he would succor Fort Sumter; and on 10 April a relief expedition sailed from New York. The Confederates reacted on 12 April 1861 by bombarding the fort, which fell two days later. This incident crystallized Northern opinion in favor of preservation of the Union, and on 15 April Lincoln issued a call to State governors for militia to suppress the rebellion. The decision to use force caused North Carolina, Tennessee, Arkansas, and Virginia (less the part that became West Virginia) to join the Confederacy. Four slave States-Delaware, Maryland, Kentucky, and Missouri-remained in the Union, although the Confederacy claimed Kentucky and Missouri.

TROOPS INVOLVED. Union Forces. In January of 1861 the Regular Army, with an authorized strength of 18,000, had an actual strength of 1,098 officers and 15,304 enlisted men. Most though not all of the Southern-born officers, who constituted about a third of the officer corps, resigned their commissions when war came and joined the Confederacy.

The great majority of individuals serving in the Union forces during the war were volunteers. On 15 April 1861 Lincoln called upon the loyal states for 75,000 militiamen to serve for three months. When it became apparent that a major war was in the offing, the President, by an Executive Order issued on 3 May (which was later approved by Congress), established 40 regiments of volunteers (42,034 men) to serve for three years or the duration of the war. The same order increased the size of the Regular Army (which remained intact throughout the war) by authorizing additional regiments with a total strength of 22,714 men. By acts of 22 and 25 July 1861, following the Union defeat at Bull Run, Congress authorized the President to accept the services of 500,000 men for three years or the duration. Subsequent acts provided authority for calling additional volunteers. The President was also authorized to call out militia units for short periods of service.

The response to early calls for volunteers was enthusiastic, but after two years of bloodshed there was difficulty in securing recruits. Therefore, on 3 March 1863, Congress passed the En

rollment Act, the Nation's first national draft law, which also removed statutory limits on the size of the Army. Although the number drafted was relatively small, the Act had the desired effect of stimulating volunteering.

At the beginning of 1861 the population of the free northern States was about 18,900,000. The four slave States that remained with the Union had a white population of nearly 2,600,000 and 429,400 slaves. (These four States furnished men to both sides in about equal numbers.) From this population the total number of individuals who served in the Union forces in the period 18615 was 2,213,363 (Army, 2,128,948; Navy and Marines, 84,415), according to figures released by the Department of Defense. Peak strength of the Union ground forces was achieved in May 1865 when 1,000,692 personnel (including 176 USMA Cadets) were on active duty.

Union forces suffered a total of 364,511 deaths during the war. Battle deaths (including died-of-wounds and prisonerof-war deaths) totaled 140,414 (Army, 138,154; Navy, 2,112; Marines, 148). Deaths from other causes totaled 224,097 (Army, 221,374; Navy, 2,411; Marines, 312). Wounds not mortal totaled 281,881 (Army, 280,040; Navy, 1,710; Marines, 131). The total death figure given above is believed to be somewhat smaller than the actual number, since the records, particularly those from Confederate prisons, are far from complete.

Confederate Forces. Authoritative statistics for the Confederate forces are not available. The white population of the Confederate States in 1861 was about 5,450,000 and the slave population about 3,521,000. Estimates of the number who served in the Confederate Army range from 600,000 to 1,500,000; it seems probable that the figure was actually around 900,000. As regards casualties, the following partial statement of deaths, based on incomplete returns, appears in the Final Report of the Provost Marshal General (1863-1866): total deaths, 133,821; killed in action, 52,954; died of wounds, 21,570; died of disease, 59,297. In addition, published statistics on the number of Confederates who died in

northern prisons range from 25,976 to 30,716.

OVERALL STRATEGY. The North had much greater manpower and resources, and overwhelming naval superiority; but to attain its end it had to defeat the Confederate Army and force the South to dissolve the Confederacy. This called for an offensive strategy, which in its final form had four principal aims: (1) to blockade the Confederate coastline; (2) to take and hold the line of the Mississippi; (3) to strike south from the Ohio Valley through Kentucky and Tennessee, into Georgia, east to Savannah, and then north toward Richmond; (4) to destroy the Army of Northern Virginia, which from time to time threatened to capture Washington and twice invaded the North. The blockade was fairly effective from the start, and became more so; and the Mississippi was completely controlled in a little over two years. But it took nearly four years to break into and push through the heart of the deep South. The principal reasons were difficult terrain which was strongly held. long lines of communication in hostile territory, and the valor and fighting qualities of Confederate soldiers. It also took nearly four years to carry out a successful Virginia campaign and destroy the Army of Northern Virginia; the chief reason here was the generally excellent leadership of the Confederate armies, which was not matched on the Union side until 1864. Another reason why the North was so long in attaining its ends was that it did most of the attacking. and the weapons of the period gave a considerable advantage to the defenders. The strategy of the South was necessarily defensive. Its only hope lay in holding the vital parts of its territory. meanwhile working by military or diplomatic means for a "break." To this end, Confederate foreign policy aimed to get Britain and France, plus other European nations, to recognize the Confederacy, and perhaps to intervene to break the blockade or to mediate and end the war. At the same time the Confederacy cherished a hope that internal dissensions, war weariness, or momentary panic following some military dis

aster might cause the North to break off the fight. The occasional Confederate offensives, as in the Antietam and Gettysburg Campaigns, were directed to those ends. None of the "breaks" which were hoped for was inherently impossible, but none of them was realized.

MAJOR BATTLES AND CAMPAIGNS." Campaigns of 1861-1862. The first campaign of the Civil War was Sumter (12-13 April 1861). Fort Sumter, located on an island in Charleston Harbor, with its 90-man garrison commanded by Maj. Robert Anderson, was besieged by the Confederates late in December 1860. Anticipating a Union attempt to reinforce the garrison, Brig. Gen. Pierre G. T. Beauregard, commander of Confederate forces in the Charleston area, demanded the surrender of the fort on 11 April 1861. Anderson rejected the demand. On the following morning Confederate batteries ringing the harbor began a heavy 34-hour bombardment of the fort. The Federal garrison vigorously returned the fire, but the result was inevitable. Anderson surrendered on 13 April with the honors of war, and was permitted to evacuate his command by sea on the following day.

After Sumter both sides energetically raised troops and prepared for war. Northern public opinion demanded immediate action, preferably an advance against Richmond, and the Confederate moves to defend the approaches to that city assumed the appearance of an intention to attack Washington. Late in June 1861, with the terms of 3-month militiamen nearing an end, Lincoln decided to attack. By this time some 50,000 Union troops had been assembled in the Washington area under the command of Brig. Gen. Irwin A. McDowell, and a force of 18,000 Federals under Brig. Gen. Robert E. Patterson was stationed at Martinsburg for the purpose of bottling up a Confederate force in the Shenandoah Valley. Opposing the Federals were about 20,000 Confederates under Beauregard at Manassas, 30 miles southwest of Washington, and about 11,000 under Brig. Gen. Joseph E. Johnston in the Shenandoah Valley.

Lincoln's decision to attack resulted

in the Bull Run Campaign (16-22 July 1861) which the Confederacy identified as the First Manassas Campaign. McDowell left Washington on 16 July with around 35,000 troops and moved slowly 20 miles west to Centreville, Va. Learning of the movement, Johnston adroitly slipped away from Patterson and shipped 9,000 reinforcements by rail to Beauregard, who deployed his army along a stream north of Manassas known as Bull Run. McDowell attacked on 21 July 1861. The main body of his attacking force crossed Bull Run at Sudley Springs and succeeded in rolling back Beauregard's left flank. But the retreating Confederates rallied on a low ridge behind a brigade led by Brig. Gen. Thomas J. Jackson, who that day earned the name "Stonewall." After two hours of fighting Beauregard staged a counterattack that drove the Federals from the field in retreat. Of the troops in the area, not more than 18,500 Federals and possibly 18,000 Confederates got into the fight. The number of casualties is difficult to determine, but a fair estimate puts the Union loss at 500 killed, 1,000 wounded, and 1,200 missing and the Confederate loss at 400 killed, 1,600 wounded, and 13 missing. The wide variety of uniforms worn by participants in the battle had caused much confusion, which led subsequently to the adoption of a gray uniform for Confederate troops and blue for the Federals.

The North was spurred to greater effort because of the defeat at Bull Run, while the South tended to relax in an atmosphere of overconfidence. Nevertheless, both sides spent the remainder of 1861 in earnestly preparing for a hard war. During this period Maj. Gen. George B. McClellan replaced McDowell as commander of the forces around Washington (the Army of the Potomac); and he became General in Chief late in 1861, when the aging Lt. Gen. Winfield Scott retired from active duty. Another important personnel change came in January 1862 when Lincoln dismissed Simon Cameron and named Edwin McM. Stanton as Secretary of War.

Except for the capture of Fort Hatteras and Clark, N. C., and of Port

Royal, S. C., and a battle at Wilson's Creek, Mo., in August, there were no significant military actions during the latter half of 1861.

The first important operation in 1862 took place in the Western Theater, where Federal forces were divided into two commands: one under Brig. Gen. Carlos Buell at Louisville, the other under Maj. Gen. Henry W. Halleck at St. Louis. Facing Buell and Halleck was Gen. Albert Sidney Johnston with 43,000 Confederate troops, occupying a line of forts and camps that extended from Cumberland Gap in Virginia, through Bowling Green, Ky., to New Madrid and Island No. 10 on the Mississippi. To protect a lateral railroad, vital to their communications, the Confederates had built Fort Henry on the Tennessee River and Fort Donelson on the Cumberland. The two forts were on the northern border of Tennessee and only 10 miles apart.

In February 1862 Halleck effected a strategic penetration of the center of Johnston's line by the Henry and Donelson Campaign (6-16 February 1862). Federal troops under Brig. Gen. Ulysses S. Grant moved on boats up the Tennessee River to a point near Fort Henry, landed, and marched overland to seize the fort. Brig. Gen. Lloyd Tilghman sent most of his garrison to Fort Donelson, and on 6 February surrendered to Flag Officer Andrew H. Foote, whose river flotilla had subjected the fort to a gunboat bombardment. Grant at once turned against Fort Donelson, which he invested on 12 February with a reinforced command of more than 25,000 men. Meanwhile the fall of Fort Henry had rendered the Confederate position at Bowling Green untenable. Johnston had therefore sent 12,000 reinforcements to Fort Donelson, bringing its strength up to about 21,000 men, and retired toward Nashville with about 14,000 men. Fort Donelson was a strong position, and gunboats attempting a bombardment were roughly handled. Grant prepared to lay siege, but when a Confederate sortie failed he made an attack. This resulted in the surrender of the fort and 11,500 Confederate troops by Brig. Gen. Simon B. Buckner on 16 February 1862. A number of Confederate units were able to escape shortly before the capit

ulation. Union losses at Donelson were 500 killed, 2,108 wounded, and 224 missing. Confederate losses, aside from prisoners, were about 2,000 killed and

wounded.

The beginning of the Henry and Donelson Campaign also marked the beginning of the longer Mississippi River Campaign (6 February 1862-9 July 1863) which included several campaigns and engagements, and ended with the fall of Vicksburg and the surrender of Port Hudson in July 1863.

After the Henry and Donelson success, Lincoln unified command of the four western armies under Halleck. The new command, with a total strength of more than 100,000 men, consisted of Brig. Gen. Samuel Curtis' Army of the Southwest in Missouri and Arkansas, Grant's Army of the Tennessee, Buell's Army of the Ohio, and Maj. Gen. John Pope's Army of the Mississippi.

Halleck's next move was against A. S. Johnston at Corinth. Buell moved to Savannah (Tenn.) on the Tennessee River, and Grant moved to Pittsburg Landing nine miles below Savannah. Johnston promptly advanced against Grant's force with some 40,000 men, and achieved surprise in an attack launched early on 6 April 1862 in the vicinity of Shiloh Church. Johnston was killed, and Beauregard assumed command during the first day's fighting, which went well for the Confederates. On the second day, with help from Buell, Grant counterattacked and regained lost ground, upon which the Confederates withdrew to Corinth. There was no pursuit. At Shiloh (6-7 April 1862), of nearly 63,000 Federals engaged, 1,754 were killed, 8,408 wounded, and 2,885 were missing. Confederate losses were 1,723 killed, 8,012 wounded, and 959 missing.

Pope's Army of the Mississippi, in cooperation with Foote's river flotilla, took Island No. 10 and New Madrid, Mo., on 7 April 1862. Pope's force then joined the rest at Pittsburg Landing, where Halleck was massing his forces. Shortly thereafter Halleck began a slow, careful advance on Corinth. When he arrived there on 30 May he found that Beauregard had left. Meanwhile Capt. David G. Farragut, with 8 steam sloops and 15 gunboats, had sailed up the Mississippi from the Gulf on 24 April, and