Unattached Companies Massachusetts Volunteer Militia

Twenty-six companies were mustered into the Union Army during 1864-1865, several of them reorganizing for additional terms of service.

Beginning in April 1864, companies of infantry were needed for guard and garrison duty along the coast of Massachusetts; to be stationed at the numerous military posts located there for a ninety-day period.

Five other companies were detached from existing regiments of the Massachusetts Militia to finish the required roster.

Their term of enlistment soon ending, a call for 100-day companies was then ordered in July and August 1864 to fill the soon to be vacant positions at the coastal forts.

In late October 1864, the office of the Adjutant General released orders to the commanding officers of the "Companies of One Hundred Days Troops belonging to Massachusetts, now doing garrison duty at the forts on the coast",[1] to reenlist their commands for one year, and to fill with new recruits any positions held by those men not choosing to rejoin.