The Army of the Potomac, established in 1861, played a crucial role during the American Civil War as the principal army of the Union in the Eastern Theater. It was involved in numerous significant battles, including Antietam, Gettysburg, and the Overland Campaign, and underwent various leadership changes, significantly impacting the war's outcome. The army, which had seen massive casualties and faced logistical challenges, was a symbol of the Union's efforts to preserve the nation during the brutal conflict. As the war came to an end in April 1865, with the Confederate surrender at Appomattox Court House, plans were set in motion for the disbandment of military forces that had been a formidable presence throughout the conflict.

In June 1865, the process of disbanding the Army of the Potomac officially began. The disbandment involved multiple steps, from inspecting the soldiers to processing their final payments and ensuring their safe return to civilian life. Many soldiers expressed mixed feelings—while some celebrated their return to families after years of separation, others were apprehensive about the transition to a peacetime economy, especially in a society still grappling with the effects of war, economic turmoil, and the newly freed slaves' social integration. The event signified a major shift in the U.S., signaling the end of the military mobilization and the start of a new era of reconstruction.