Apr. 4, 1825 Pittsburgh Allegheny County Pennsylvania, USA
Aug. 19, 1901
John married Martha Callender Mahon of Carlisle, PA. Martha was daughter from John Duncan Mahon's first marriage. His second marriage was to John Irwin's aunt Agnes Mary Irwin Rose.
After the birth of their first child, Mary Irwin, John and Martha Irwin moved to Fort Wayne, Indiana along with his widowed mother. John was a doctor, Cashier of the Merchant National Bank and Superintendent of Fort Wayne City Schools.
Late in life, John and Martha lived with daughter Mary Irwin in Lafayette, Ind where Mary was Private Secretary to the President of Purdue University.
from the Ft. Wayne Community School website: Irwin Elementary School is named for John S. Irwin, who served as superintendent of Fort Wayne Community Schools from 1875-1896. His first career was as a doctor at Mercy Hospital in Pittsburgh. When his health failed, he became a bookkeeper for the private banking firm of Allen Hamilton in Fort Wayne. He stayed in banking for about 20 years until his health, again, forced him to resign. In 1865, when he was still a banker, he was appointed to the city school board. Ten years later, when Superintendent Dr. James Smart was elected state superintendent of public instruction (and later president of Purdue University), Dr. Irwin was elected superintendent of the city schools.