Men of the 7th Cavalry had previously served in almost all the regiments that existed in the Army of 1876. They had served in in all 5 artillery regiments, in all of the 7 other white cavalry regiments, and in 21 of the 23 white infantry regiments. They also served as hospital stewards, post commissary sergeants, and a post bandsman, in the engineer battalion, the West Point cavalry detachment, the Ordnance Department, and the Navy and the Marines. Part of the reason for this wide spread service was desertion, but many men completes enlistments in more than one regiment. 185 men and 4 civilian packers had prior service. Civil War service in the U. S. Volunteers was not considered.
Not all these men were present with the regiment at the LBH.
The largest single contingent of men from other regiment was from the 5th Cavalry. My old regiment the 8th Cavalry was represented by 10 men. They had perfect attendance at the LBH. Four were killed with Custer. One more was killed and 2 were wounded with Reno; one of the wounded died. The total of 7 casualties equaled the highest total casualties the 8th Cavalry sustained in only 2 of its over 100 Indian War engagements, and the six fatalities was not equaled.