Allen, John Stevenson was born on October 20, 1857 in at Mercer, Pennsylvania, United States. Son of Cochran and Elizabeth (Wilson) Allen.
Bachelor of Arts, Westminster College, Pennsylvania, 1882. Graduate Union Theological Seminary, New York, 1885 (Doctor of Divinity, 1906).
Ordained to Presbyterian ministry, 1885. Pastor, Westchester, New York, 1885-1888, Patterson, New York, 1888-1892, New York Avenue Reformed Church, Newark, 1892-1906, Marble Collegiate Church, New York, 1906-1911. Assistant pastor Fifth Avenue.
Married Edith Hedden, of Orange, New Jersey, June 6, 1888.