1819 January 8:
New Portland post office opened. (source: Maine Philatelic Society. 1995. The Post Offices of Maine: A Rarity Guide.)
1935 February 14:
The circular postmark is 31–33 mm in diameter.
1984 March:
New Portland post office closed. (source: Maine Philatelic Society. 1995. The Post Offices of Maine: A Rarity Guide.)
North New Portland
1833 January 21:
North New Portland post office opened. (source: Maine Philatelic Society. 1995. The Post Offices of Maine: A Rarity Guide.)
1934 October 25 through 1940 December 20:
The circular postmark is 32–33 mm in diameter. The outside vertical height of the four horizontal bars to the right of the circle is 19–20 mm.
1949 March 5 through 1950 February:
The circular postmark is 29–31 mm in diameter.
today:
North New Portland post office is still in operation.
