Dilley was born in Cortland, Ohio, USA, on 21 May 1864, to parents Moses Cooper Post (1822–1903) and Elvila Freer (1823–1891). She had eight siblings.
On 24 April 1895, she married Elmer O. Dilley (1861–1931). Her husband was a probate judge in Trumbull County. The couple had no children. In 1952, she moved from Warren, Ohio to Pittsburgh to live with her niece. She was a member of the First United Methodist Church in Warren since 1893, but she never transferred her church membership.
Dilley passed away in Shadyside Hospital in Pittsburgh, Pennsylvania, USA, on 10 November 1974, at the age of 110 years, 173 days.
Her age was verified by Jimmy Lindberg, Gabriel Ainsworth, and Anson Davis, and validated by LongeviQuest on 15 February 2024.
* “It’s Quips, Not Quits, On Her 110th Birthday” – Pittsburgh Post-Gazette, 21 May 1974
* “Alta Dilley, Point Breeze Centenarian” – Pittsburgh Post-Gazette, 11 November 1974
* Alta B. Post – Geni
* Alta B. Dilley – Find A Grave
* Alta B (Post) Dilley (1864 – 1974) – WikiTree