Massachusetts Volunteer Militia

The Massachusetts State Defense Force
Massachusetts State Defense Force insignia.
Active	2011–2016 (deactivated)
Country	United States
Allegiance	Massachusetts
Branch	Army
Type	State defense force
Role	Military reserve force
Part of	Massachusetts Organized Militia
Garrison/HQ	Hanscom AFB, Massachusetts
Website	MSDF Official Website
Commanders
Civilian leadership	Governor Charlie Baker (Governor of the State of Massachusetts)
State military leadership	Brigadier General Gary Smith

The Massachusetts State Defense Force (MSDF) is the State Defense Force of the state of Massachusetts. The purpose of the Massachusetts State Defense Force is to augment the Massachusetts National Guard during emergencies in the state, especially when some or all of the National Guard is deployed. The MSDF is an all-volunteer state military force which reports directly to the State Adjutant General and is under the command of the Governor of Massachusetts. Like the National Guard, members have regular civilian careers and only meet for drills one weekend per month unless activated by the Governor during an emergency. The guard is headquartered at Milford, Massachusetts, in the same building as the National Guard. The director of the guard is appointed by The Adjutant General of Massachusetts (TAGMA). The Massachusetts State Defense Force is authorized by both the Constitution of Massachusetts and chapter 33 § 10 of the Massachusetts General Laws.

The MSDF is composed of volunteers who operate solely within Massachusetts and may not be called into federal service. The MSDF assists the United States National Guard forces, assumes state missions when the National Guard is deployed, provides emergency support during disasters, and assists in color guards and funeral details.

The Massachusetts General Court formed the MSDF's predecessor in 1863, which served until its disbandment in 1866. During the American Civil War, Massachusetts provided multiple units to support the Union cause. The Massachusetts militia was reformed in 1898 as the Massachusetts Provisional Militia for the Spanish–American War before again being disbanded in 1899. During the course of the war, five infantry regiments and one artillery regiment from the Massachusetts Provisional Militia were deployed.