Initially raised as 10 companies of 100 men, A,D & H from New York, B from Albany N.Y. C, K & I from Michigan, E from New Hampshire, F from Vermont, and G from Wisconsin.
Normal volunteer units received replacements to the original complement only from returning wounded or sick soldiers. The sharpshooters recruited in their original recruiting states to try to maintain numbers. This was not totally effective, by mid 1863 company effectives varied from 40 to 60 rifles and numbers would continue to vary until the regiment was amalgamated with the 2nd Regiment in 1865.
|September 9th||Co E Organised New Hampshire|
|September||Regiment concentrates at Weehawken New Jersey|
|September 24th/25th||Move to Washington Camp of instruction|
|November 29th||Mustered into Army Served Unattached, Martindale’s Brigade, Fitz John Porter’s
Division, Army of the Potomac. Duties in the defence of Washington.
|March Unassigned||1st Division, 3rd Army Corps, Army of Potomac|
|May||3rd Brigade, 1st Division, 5th Army Corps, Army of Potomac|
|March||3rd Brigade, 3rd Division, 3rd Army Corps, Army of Potomac|
|June||2nd Brigade, 1st Division, 3rd Army Corps, Army of Potomac|
|September||3rd Brigade, 1st Division, 3rd Army Corps, Army of Potomac|
|March||2nd Brigade, 3rd Division, 2nd Army Corps|
|August 19th||Co. A mustered out|
|August 28th||Co. D mustered out|
|December 31st||Consolidated with 2nd Regiment US Sharpshooters|
The regiment lost during service 10 officers and 143 enlisted men killed and mortally wounded plus 1 officer and 128 enlisted men by disease. A total of 282 deaths in service.