The Regiment was authorized on April 23, 1775 in the Massachusetts State Troops as Heath’s Regiment. Organized in spring 1775 at Roxbury to consist of 10 companies from eastern Suffolk County. Adopted on June 14, 1775 into the Continental Army and assigned to the Main Continental Army. Reassigned on February 9, 1777 from McDougall’s Brigade and assigned to the Northern Department. It was assigned on March 13, 1777 to the Northern Department and assigned to the Highland’s Department. It was assigned on June 12, 1777 to the 1st Massachusetts Brigade, an element of the Highland’s Department. 1st Massachusetts Brigade relieved 1 July 1, 1777 from the Highland’s Department and assigned to the Northern Department. Reorganized on May 12, 1779 to consist of 9 companies. Re-designated on August 1, 1779 as the 3rd Massachusetts Regiment. Reassigned on June 12, 1783 from the 3d Massachusetts Brigade and assigned to the 1st Massachusetts Brigade, an element of the Highland’s Department. Disbanded on November 3, 1783 at West Point, New York.