Adam Philips Leighton was born to Adam and Julia Ann (Leighton) Leighton on April 6, 1851 in West Falmouth, Maine. Adam married Isadore Mary Butler (b. 1852), daughter of Alonzo and Mary (Dodge) Butler of Portland on June 30, 1873.
Adam Leighton was elected mayor of Portland, Maine three times. In 1902 he built an impressive home on the Western Promenade in Portland.