1852 August 16:
East Holden post office opened. (source: Maine Philatelic Society. 1995. The Post Offices of Maine: A Rarity Guide.)
1872 July 16:
East Holden post office closed. (source: Maine Philatelic Society. 1995. The Post Offices of Maine: A Rarity Guide.)
1884 April 24:
East Holden post office re-opened. (source: Maine Philatelic Society. 1995. The Post Offices of Maine: A Rarity Guide.)
1935 August 27:
The circular postmark is 28–29 mm in diameter.
1945 September 26 through 1952 August 11:
The circular postmark is 32–34 mm in diameter. Note that the four horiontal bars nearly touch the circle of the postmark.
1956 June 19 through 1956 November 14:
The circular postmark is 32–33 mm in diameter. Note that the four horiontal bars are clearly separated from the circle of the postmark.
1995 Fall:
East Holden post office closed. (source: Maine Philatelic Society. 1995. The Post Offices of Maine: A Rarity Guide.)
Holden (1)
1852 April 22:
The former East Brewer (2) post office was renamed as Holden (1) post office. (source: Maine Philatelic Society. 1995. The Post Offices of Maine: A Rarity Guide.)
1852 August 16:
Holden (1) post office renamed as East Holden post office. (source: Maine Philatelic Society. 1995. The Post Offices of Maine: A Rarity Guide.)
1872 July 16:
The former East Holden post office renamed as Holden (1) post office. (source: Maine Philatelic Society. 1995. The Post Offices of Maine: A Rarity Guide.)
1884 April 24:
Holden (1) post office renamed as East Holden post office. (source: Maine Philatelic Society. 1995. The Post Offices of Maine: A Rarity Guide.)
1995 Fall:
The former East Holden post office was renamed as Holden (1) post office. (source: Maine Philatelic Society. 1995. The Post Offices of Maine: A Rarity Guide.)
2019 May 10:
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 approximately 16 mm.
today:
Holden (1) post office is still in operation.