The Third Brigade left Camp California, near Alexandria, Va., August 28, on the Fairfax and Alexandria turnpike. Arrived at Centreville the night of the 30th, where it encamped until the night of September 1. Tool up the march again, and encamped near Fairfax for the night. Reached Camp California, Va., again on September 2, and pitched tents and remained until September 6.
Marched across Long Bridge;encamped on September 7 near Georgetown, and marched through Tennalytown, Rockville, Barnesville, and Darnestown, to the right of Sugar Loaf Mountain, through Jefferson, towards the Catoctin Mountain. Marched through Burkittsville on the 15th, to support Brigadier General W. T. H. Brooks at Crampton's Pass. Remained here until Wednesday morning, the 17th. Moved with the division toward Shaprsburg, arrived at the battle-field of Antietam Creek about 10 a.m., went into action, and was under fire until 12 noon, the 18th, when relieved by Couch's division.
The total loss of the different regiments composing this brigade was as follows:
The Thirty-third New York Volunteers, 6 killed, 41 wounded; Forty-ninth New York Volunteers, 2 killed, 21 wounded; Seventh Maine, 12 killed, 63 wounded, and 20 missing; Seventy-seventh New York Volunteers, 6 killed, 26 wounded; Twentieth New York Volunteers, 38 killed, 96 wounded, and 11 missing. Total, 64 killed, 247 wounded, and 31 missing; in all, 342.
Remained near Sharpsburg until the 22d, and moved up near Bakersville, where the brigade is now encamped.
September 1, a.m., bivouacked between Alexandria and Centreville, moved to within 2 miles of Centreville, and returned to Germantown.
September 2, 5 p.m., brought up the rear of army on the retreat to Alexandria.
September 3, 2 a.m., bivouacked near Alexandria.
September 4, moved to vicinity of Chain Bridge, on the Virginia side.
September 5, 5 p.m., crossed Chain Bridge, and moved by river road 3 miles beyond Tenallytown.
September 6, reached Offutt's Cross-Roads.
September 9, moved to Seneca.
September 10, moved to Poolesville.
September 12, moved to Barnesville.
September 13, moved to Licksville.
September 14, moved to Jefferson, at 8 p.m., near Burkittsville, and joined General Franklin's corps.
September 15, moved to vicinity of Rohresville.
September 17, moved to Sandy Hook and back to vicinity of Sharpsburg.
September 18, in line of battle at Sharpsburg.
September 19, through Sharpsburg.
September 20, moved to cross-roads near Williamsport, skirmishing in front.
September 21, enemy retreated across the river from Williamsport.
September 23, moved to Downsville.
September 30, at Downsville.
*Third Brigade only reported.