The 20th Indiana Volunteer Infantry Regiment was an infantry regiment that served in the Union Army during the American Civil War. The Regiment was officially raised on July 22, 1861, by William L. Brown, the first Colonel of the Regiment, in response to President Lincoln's call for volunteers. At the time of muster, the regiment had 9 fighting companies lettered A-K along with a staff company for a total of 10 companies, roughly 1000 men. The 20th Indiana saw engagements in most of the major battles of the American Civil War, including the action between the first ironclads at Hampton Roads, the Battle of Fredericksburg, the Battle of Gettysburg, and the Siege of Petersburg. The Regiment was part of the 1st Brigade, 3rd Division, III Corps for the duration of the war. Service The 20th Indiana Volunteer Infantry was organized at Lafayette, Indiana, on July 22, 1861. The regiment mustered out of service on July 12, 1865. It spent the entirety of its service in the eastern theater of the war. Creation of the Regiment William L. Brown, a veteran of the Mexican–American War, was given permission by the United States Secretary of War to raise a volunteer rifle regiment to be mustered into service with the United States Army. Brown went across Indiana talking to friends in order to raise enough companies for the regiment. This was accomplished by various people in various counties over the course of June, 1861. Brown set the date of July 4, 1861, as the date for all companies to rendezvous in Lafayette, Indiana, in order to be properly mustered into service. The Regiment was assembled between July 20–22, with the latter date being when it was officially mustered into service. The mustering process was markedly simple, due to the dire need of fighting men. The process consisted of the various companies being assembled in a large, open field. A mustering officer would walk among the ranks of the companies, looking at the general physical appearance of each man along with his hands. There are at least two documented instances of the mustering officer stopping to question the ability or age of prospective volunteers. The first instance involved a man by the name of Smith who had lost is right index finger in a farm accident. The mustering officer questioned how accurate Smith could be with a weapon, if he could hold a weapon