Born December 25, 1835, at Lehigh Gap, Allen was the third son of Senator Thomas and Catherine (Hagenbuch) Craig, was reared at Lehigh Gap, Carbon County; graduated from Lafayette College in 1855; read law with M. M. Dimmick of Mauch Chunk; and was admitted to the bar in June, 1858. Entered private practice at Mauch Chunk; elected district attorney of Carbon County, 1859; served as a member of the emergency militia during the Civil War; was a member of the state House of Representatives, 1865-1867; and the state Senate, 1879-1882. He married Anna Isabelle Douglas, 1866, the daughter of the superintendent of the Lehigh coal and navigation company. As counsel to the Lehigh Valley Railroad, the Senator served as a prosecutor against the Molly Maguires, assisting (former Senator) Francis Wade Hughes, who served as chief prosecutor. He died December 31, 1902.