The 1st Sergeant was the mustering sergeant of the company; the second sergenat was sometimes referred to as the ordinance sergenat, but I have no clue as to what, if anything, the 3rd sergeant was called. In pre-radio communications days, a substantial number of sergeants were needed to help maintain order. Companies not only included the Captain and 1st and 2nd lieutenants, but also included a third lieutenant, commonly called a brevet leiutenant. There were also 5 or 6 corporals in infantry company organizations, and I have seen the number of corporals in artillery batteries run as high to 10 corporal.