The 16th Infantry Regiment was constituted on 3 May 1861 as the 1st Battalion, 11th U.S. Infantry. The 11th U.S. Infantry was the first of nine “New Army” infantry regiments authorized by President Abraham Lincoln that spring. As such, the regiment’s organization was a departure from the pre-war U.S. Army infantry regiments (1st through 10th) which consisted of a regimental headquarters, band, and ten infantry companies. Under that organization, the Old Army regiments consisted of a little over 1,000 officers and men. The New Army regiments consisted of a regimental headquarters, band, and three battalions of eight companies each. At full strength one of the newer regiments would consist of something over 2,450 officers and men. In addition to the new regimental structure, the newer regiments consisted of a Regimental Recruiting Service and the Regimental Recruit Depot. Niether of these organizations were authorized addtional personnel, however.