During the American Civil War, Indianapolis was mostly loyal to the Union cause. Governor Oliver P. Morton, a major supporter of President Abraham Lincoln, quickly made Indianapolis a rallying place for Union army troops. On February 11, 1861, President-elect Lincoln arrived in the city, en route to Washington, D.C. for his presidential inauguration, marking the first visit from a president-elect in the city's history.[45] On April 16, 1861, the first orders were issued to form Indiana's first regiments and establish Indianapolis as a headquarters for the state's volunteer soldiers.[46][47] Within a week, more than 12,000 recruits signed up to fight for the Union.[48]
Indianapolis became a major logistics hub during the war, establishing the city as a crucial military base.[49][50] Between 1860 and 1870, the city's population more than doubled.[43] An estimated 4,000 men from Indianapolis served in 39 regiments, and an estimated 700 died during the war.[51] On May 20, 1863, Union soldiers attempted to disrupt a statewide Democratic convention at Indianapolis, forcing the proceedings to be adjourned, sarcastically referred to as the Battle of Pogue's Run.[52] Fear turned to panic in July 1863, during Morgan's Raid into southern Indiana, but Confederate forces turned east toward Ohio, never reaching Indianapolis.[53] On April 30, 1865, Lincoln's funeral train made a stop at Indianapolis, where an estimated crowd of more than 100,000 people passed the assassinated president's bier at the Indiana Statehouse.[50][54]