When John Morton McCormick was born on 1 July 1848, in Grant, Indiana, United States, his father, John L. McCormick, was 43 and his mother, Diana Baldwin, was 36. He married Rebecca J Tomlinson on 14 September 1878, in Grant, Indiana, United States. They were the parents of at least 3 sons and 3 daughters. He lived in Van Buren Township, Madison, Indiana, United States in 1900 and Fairmount, Grant, Indiana, United States in 1910. He died on 5 February 1913, in Center Township, Grant, Indiana, United States, at the age of 64, and was buried in Madison, Indiana, United States.