Authorized on April 23, 1775 in the Massachusetts State Troops as Little's Regiment. The regiment was organized in spring 1775 at Cambridge to consist of 10 companies from northeastern Middlesex and Hampshire Counties, Massachusetts; and Hillsborough County, New Hampshire. Adopted on June 14, 1775 into the Continental Army and assigned to the Main Continental Army. It was assigned to the on July 22, 1775 to Greene's Brigade, an element of the Main Continental Army. Re-organized and redesignated 1 January 1776 as the 12th Continental Regiment, an element of Greene's Brigade to consist of 8 companies. Reassigned on August 12, 1776 from Greene's Brigade and assigned to Nixon's Brigade, an element of the Main Continental Army. Disbanded during February 1777 at Morristown, New Jersey and Peekskill, New York.