Battle of Antietam: Two Great American Armies Engage in Combat
The opposing armies at Antietam were two very different forces commanded by two very different men.
By Ted Alexander
On September 17, 1862, two of America's greatest armies engaged in mortal combat at the Battle of Antietam (or Sharpsburg). Both of these forces were in their infancy. The Army of the Potomac and the Army of Northern Virginia would go on to greater glories on other fields. But perhaps never again would they face so many structural challenges as in the confusing days of September 1862. A comparison of the armies helps to clarify those challenges and identifies the strengths and weaknesses inherent in each command.
General George B. McClellan was the 35-year-old scion of a noted Pennsylvania medical family with roots dating back to colonial New England and Mayflower. McClellan was well schooled in military matters, ranking second in the famous West Point class of 1846. He had experience both in the Mexican War and as an observer of European armies during the Crimean War. Nevertheless, his frequent caution in combat, coupled with a conservative outlook on how the rebellion should be put down, proved to be his undoing as an army commander. Military successes in western Virginia early in the war brought him favor with the Lincoln administration. This led him back to the seat of government and appointment as commander of the Army of the Potomac, and soon the position of general-in-chief.
McClellan's Peninsula campaign in the spring of 1862 brought the Union army closer to the Confederate capital in Richmond than any other time until Ulysses S. Grant's Overland campaign two years later. But McClellan failed to capture his objective. This and ongoing disagreement with the administration cost him his command, but only temporarily. The subsequent defeat of Union Maj. Gen. John Pope's Army of Virginia in the Second Manassas campaign that August opened the door for McClellan once again. As the Army of Northern Virginia prepared to cross the Potomac into Maryland, Abraham Lincoln was faced with his worst crisis since taking office. McClellan was restored to command and charged with protecting the capital and stopping the Confederates. Within days he organized a new Army of the Potomac in the camps outside Washington.
General Robert E. Lee was a Virginia aristocrat whose lineage included some of the great political and military figures of the early days of the republic. But this is where the similarities between the two commanders quickly diverge. Lee was 55 years old at the time of the Maryland campaign. Unlike McClellan, who in the prewar years had left the Army for lucrative work in the railroad industry, Lee had spent more than 30 years in the Army. During this period he was a cavalry commander, engineer on many of the Atlantic coastal fortifications, superintendent at West Point and a staff officer in the Mexican War. It was in the latter position that Lee gained the valuable experience needed to lead armies in the Civil War. While McClellan often quarreled with the Lincoln administration, Lee had the full support of President Jefferson Davis and the Confederate Congress. Promoted to the rank of full general in August 1861, he took field command of General Joseph E. Johnston's army after that commander was seriously wounded at the Battle of Seven Pines on May 31, 1862. Leading the Army of Northern Virginia, the new commander drove McClellan from the Peninsula and then launched a lightning campaign into northern Virginia that culminated in the destruction and rout of Pope's army at Second Manassas. By September 4, 1862, the Confederates were crossing the Potomac into Maryland, in a campaign that would be one of the most desperate of the war for this great army.
The two armies that fought at Antietam represented a cross section of the American population. The soldiers were primarily from small towns or rural backgrounds. Union regiments claimed more urban enlistments. Around one-fourth of the Union troops were from New York. Pennsylvania was the next largest group. Nearly 25 percent of Lee's army was from Virginia, with Georgia representing a close second at about 21 percent.
Although the Civil War is generally viewed as a conflict between white Anglo-Saxon Protestants, a close examination reveals an interesting ethnic makeup among Johnny Rebs and Billy Yanks alike. Traditional groups such as the Scots-Irish and "Pennsylvania" Germans could be found on both sides. Many Southern soldiers from both ethnicities in the Shenandoah Valley shared cultural, economic and kinship ties with the same groups in south-central Pennsylvania. The influx of immigrants from Germany and Catholic Ireland was well represented, particularly in the North, with units such as the Irish Brigade and the German 5th Maryland (Union) and 20th New York. All these units acquitted themselves well at Antietam.
The famed Iron Brigade boasted Germans, Norwegians and Métis (men of French Canadian and Indian descent). Indeed, recent research by Iron Brigade scholar Lance Herdegen has uncovered the existence of at least two mulattos who passed for whites and were serving in the ranks. Jews could be found in both armies. The 5th Maryland (Union), made up almost entirely of German immigrants, fought at Bloody Lane. Their commander was Major Leopold Blumenberg, a Jewish immigrant from East Prussia. Among the Confederates opposing the 5th Maryland in the Sunken Road was the 12th Alabama. Captain Adolph Proskauer, another Jewish immigrant from Prussia, served with the 12th and was seriously wounded in the battle.
Even a solid "Anglo" command like the Texas Brigade had its minorities. Captain Decimus et Ultimus Barziza of Company C, 4th Texas, was the son of Italian immigrants. His name in Latin means "the tenth and the last" (apparently his mother had had enough of child rearing when he came along). Both Louisiana brigades in Lee's army were very cosmopolitan. Besides Louisiana French of both Creole and Acadian (Cajun) descent, the ranks were filled with men from all over the world. One study has shown that at least 24 nationalities were represented in these regiments, including Greeks, Italians, Mexicans, Brazilians and men from Martinique. The 12th South Carolina contained a number of Catawba Indians.
The Army of the Potomac
McClellan's army was put together in an amazingly short time in early September 1862 at Rockville, Md. But this new Army of the Potomac was an amalgam of a number of different commands. It was certainly not the same force that had nearly captured Richmond in the Peninsula campaign, nor was it the Army of the Potomac that would gain victory and fame at Gettysburg and other places. At Antietam McClellan had the II, V and VI corps of his original Army of the Potomac. Three corps from Pope's ill-fated Army of Virginia were also in the fold. They became the I, XI and XII corps. While the XI Corps was kept back to guard Washington, the other two played key roles in opening the Battle of Antietam. The IX Corps was comprised of Maj. Gen. Ambrose Burnside's unattached Carolina Expeditionary Force and the Kanawha Division.
The corps system was a Napoleonic innovation. The great emperor of France devised it as a miniature army containing three infantry divisions, artillery and cavalry. Such an organization provided simplification of command at the army level and flexibility in combat power. It was a major reason for the success of Napoleon Bonaparte's armies. Up to the time of the Civil War, the U.S. Army had been too small to make the corps system practical. But by 1861-62 the corps had become the building block of the huge forces being raised by both sides.
The quality of command and combat efficiency made the Army of the Potomac, numbering about 86,000, a patchwork force. The average Union regiment at Antietam had 346 men. Many of the new regiments had around 800 men. Such was the case with the 125th Pennsylvania. When the 125th engaged Brig. Gen. Jubal Early's Confederates in the West Woods, the Rebels thought that they were up against an entire Yankee brigade.