1879 March 1: [year determined from contents]
  The circular postmark is 25–26 mm in diameter.
year? May 1:
  The circular postmark is approximately 32 mm in diameter.
1894 March 30 through 1894 April 5:
  The circular postmark is 28–29 mm in diameter.
1932 December 30 through 1946 February 4:
  The circular postmark is approximately 20 mm in diameter.
date?:
  Freeport post office.
date?:
  Freeport post office.
1941 May 12:
  The circular postmark is approximately 30 mm in diameter.
today:
  Freeport post office is still in operation.
South Freeport
1854 June 17:
South Freeport post office opened. (source: Maine Philatelic Society. 1995. The Post Offices of Maine: A Rarity Guide.)
1854 December 11:
South Freeport post office closed. (source: Maine Philatelic Society. 1995. The Post Offices of Maine: A Rarity Guide.)
1856 March 22:
South Freeport post office re-opened. (source: Maine Philatelic Society. 1995. The Post Offices of Maine: A Rarity Guide.)
1913 July 21:
  The circular postmark is approximately 31 mm in diameter. The outside vertical height of the four horizontal bars to the right of the circle is 12 mm. (image side of card)
1934 June 13:
  The circular postmark is 30–32 mm in diameter. The four horizontal bars to the right of the circle are approximately 6 mm on center.
1939 November 25:
  The circular postmark is 30–32 mm in diameter. The outside vertical height of the four horizontal bars to the right of the circle is 18–19 mm.
1949 December 23:
  The circular postmark is 32–33 mm in diameter. The four horizontal bars to the right of the circle are approximately 6 mm on center.
today:
  South Freeport post office is still in operation.