The Union Army during the Civil War was essentially a volunteer army. To become an Officer of Volunteers, one only needed to raise a company. Often prominent and wealthy citizens used their money and influence to sign up a hundred men or so to make up their company. At the beginning of the war, this was fairly easy to do, as the enthusiasm for fighting for the Union was high. The Union Army of the Potomac was itself a largely volunteer army. In August of 1861 the Union Army of the Potomac formed by merging commands in Washington, Northern Virginia, and the Shenandoah. In Virginia, the primary battles took place between the Union Army of the Potomac and the Confederate Army of the Potomac (later renamed the Army of Northern Virginia in 1862). The two forces fought at the battles of Antietam, Chancellorsville, Fredericksburg, Seven Days, The Wilderness, Bull Run, and Gettysburg. The Union Army of the Potomac was led during these times by such generals, as George McClellan, Ambrose Burnside, and George G. Meade. Born in 1815, William Henry French was a veteran of the Mexican wars. He was appointed a Major General during the Civil War in November 1862. He commanded troops at Antietam, Fredericksburg, Chancellorsville, Manassas Gap, Auburn, Kelly's Ford, Brandy Station, and in the Mine Run operation. Meade considered French personally responsible for the failure at Mine Run. When the Army of the Potomac reorganized that winter, French was displaced and saw no further field service. He continued in the regular army until 1880 when he retired as Colonel 4th Artillery. He died in 1881.

Note written by Special Collections Staff