William Schouler, A history of Massachusetts in the Civil War: Volume 1

[508] United States, thirty-six regiments of infantry, three regiments of cavalry, two regiments of heavy artillery, one battalion and eight unattached companies of heavy artillery, twelve batteries of light artillery, and two companies of sharpshooters. All of these were for three years service, and were distributed as follows:—

The First, Seventh, Ninth, Tenth, Eleventh, Twelfth, Thirteenth, Fifteenth, Sixteenth, Eighteenth, Nineteenth, Twentieth, Twenty-second, Twenty-eighth, Thirty-second, Thirty-seventh, Thirty-ninth Regiments of Infantry, First Regiment of Cavalry, the Third, Fifth, Ninth, Tenth Light Batteries, First and Second Companies of Sharpshooters, were in the Army of the Potomac.

The Second, Twenty-first, Twenty-ninth, Thirty-third, Thirty-fifth, and Thirty-sixth Regiments of Infantry were in the Department of the Ohio.

The Seventeenth, Twenty-third, Twenty-fifth, Twenty-seventh Regiments of Infantry, and the Second Regiment of Heavy Artillery, were in the Department of Virginia and North Carolina.

The Twenty-fourth, Fortieth, Fifty-fourth, Fifty-fifth Regiments of Infantry, and First Battalion of Cavalry, were in the Department of the South.

The Twenty-sixth, Thirtieth, Thirty-first, Thirty-eighth Regiments of Infantry, and the Third Regiment of Cavalry, and the Second, Fourth, Sixth, Twelfth, Thirteenth, and Fifteenth Companies of Light Artillery, were in the Department of the Gulf.

The Thirty-fourth Regiment of Infantry, Second Regiment of Cavalry, First Regiment of Heavy Artillery, and the Seventh Company of Light Artillery, were in the Department of Washington.

The First Battalion, and the Third, Fifth, Sixth, Seventh, Eighth, Ninth, Tenth, Eleventh, and Twelfth Unattached Companies of Heavy Artillery, were in the Coast Defences of Massachusetts.

Shortly after this date, the Third Battalion of the First Regiment of Cavalry was permanently detached from that regiment,