Recruited in Western Massachusetts. Arrived at Washington July 28, 1861, and remained in its vicinity until the army moved to the Peninsula, in March, 1862. It was assigned to Devens's (3d) Brigade, Couch's (1st) Division, Fourth Corps. Under command of Colonel Briggs it distinguished itself at Fair Oaks, the Colonel being wounded, and the casualties amounting to 27 killed, 95 wounded, and 2 missing. Major Ozro Miller, a gallant officer, succeeded to the command, but fell, mortally wounded, soon after at Malvern Hill. Col onel Eustis was in command at Second Fredericksburg and Salem Heights, in which the casualties amounted to 10 killed, 57 wounded, and 2 missing. The brigade had been previously transferred to Newton's (3d) Division, Sixth Corps. The brigade took the field in May, 1864, under command of General Eustis, as the Fourth Brigade of Getty's (2d) Division, Sixth Corps. Colonel Parsons led the regiment in the battles of Grant's campaigns, its losses at the Wilderness amounting to 21 killed, 105 wounded, and 2 missing, -- over one-third of those engaged. A still heavier percentage of loss occurred in the various actions about Spotsylvania (15 killed, 64 wounded, and 13 missing), Major Dexter F. Parker being mortally wounded there. The action of May 12th, at Spotsylvania, was the closest and deadliest of any in which the Tenth had been engaged. On June 20, 1864, while in the trenches before Petersburg, the regiment received the orders to return home for muster-out; one of the officers was killed just before the regiment left its position to go home.