Greenfield to Montague City
Erving to Cambridge via Athol, Fitchburg, Lunenburg, Ayer, Littleton, North Acton. Arlington and Cambridge.
2A existed as early as 1933. The section between Turner’s Falls and Miller’s Falls existed as 2A. Also bearing the 2A designation was modern MA 225 from it’s end east of Lunenburg into Lexington.
By 1936, the eastern 2A had been renumbered to MA 25. 2A was reassigned to the road from Concord to Lexington. 2A then followed US 3 to Harvard University, then followed Mass Ave back to MA 2 at the Harvard Bridge.
By 1953, MA 2 was a highway east of Westminster. 2A picked up the road formerly used by 2. A bypass was built south of Athol and Orange; by 1961 2A had picked up the former Rt 2 through these towns.
Dan Vincent’s MA 2A page