9th Massachusetts Infantry

The Ninth Massachusetts Infantry, a regiment of Massachusetts Volunteers in the 2d Brigade, 1st Division, 5th Army Corps of the Army of the Potomac, was composed of ten companies of 101 men each from Boston, Salem, Milford, Marlboro, and Stoughton. Organized at Boston on May 9, 1861, it entered United States volunteer service on June 11, 1861, and was mustered out at Boston on June 21, 1864. Commanded respectively by Colonel Thomas Cass and Colonel Patrick R. Guiney, it served during three years of campaigns in Virginia, Maryland, and Pennsylvania and fought in forty two engagements, including the Peninsula Campaign, Hanover Court House, Seven Days Battles, Antietam, Fredericksburg, Chancellorsville, Gettysburg, Mine Run, and the Wilderness Campaign. During the battle of Gettysburg, the Ninth Regiment was detached from the 2nd Brigade and held this position on Round Top, where it suffered casualties of 26 men. Its total number of casualties was 863.

Pennsylvania · United States