When Allen Athearn was born on 16 March 1846, in Rising Sun, Randolph Township, Ohio, Indiana, United States, his father, Prince A Athearn, was 34 and his mother, Louisa Hastings, was 33. He married Isabella Thomson on 7 November 1878, in San Joaquin, California, United States. They were the parents of at least 1 son and 2 daughters. He lived in Elkhorn Judicial Township, San Joaquin, California, United States in 1860 and Elliott, San Joaquin, California, United States in 1870. He died on 27 November 1889, in San Joaquin, California, United States, at the age of 43, and was buried in Lockeford, San Joaquin, California, United States.