Fire Department officially established 1844
https://books.google.com/books?id=3TowAQAAMAAJ&pg=PA646&lpg=PA646&dq=dorchester+and+milton+branch+railroad+statute&source=bl&ots=HRzGFzPYoO&sig=T92ZM7lwlqf7qpZ2HC_z1GMb2k4&hl=en&sa=X&ved=0ahUKEwiG2cb5goDaAhWttlkKHaALBxIQ6AEIMTAB#v=onepage&q=dorchester%20and%20milton%20branch%20railroad%20statute&f=false
Private and Special Statutes of the Commonwealth of Massachusetts, from January 1838 to May 1848 … Boston, 1848. vol. 8, p. 645
Be it enacted by the Senate and House of Representatives, in General Court assembled, and by the authority of the same, as follows:
A fire department is hereby established in the town of Dorchester, subject to all the duties and liabilities, and with all the powers and privileges, set forth and contained n an act, entitled An Act to regulate Fire Departments,” passed on the ninth day of April, in the year one thousand eight hundred and thirty-nine. [February 5, 1844.]