John Gannon was born in 1860 in Massachusetts. Before his incarceration, Mr. Gannon worked as a painter and a day laborer while living in Chelsea.
Mr. Gannon was incarcerated in the Massachusetts State Prison on June 11, 1889, and again on April 14, 1894. He died there of acute pneumonia at 4:35 A.M. on February 2, 1903, at 41.
