J.C. Hannon was born in England in 1828, and came to the United States with his parents five years later. The family settled in Ohio where his parents remained the rest of their lives. In 1859, J.C. Hannon started westward across the plains, and after spending four years in Nevada, he came to California and made his home in San Jose, where he married Elizabeth Carr. In 1869, he moved to Los Angeles County and settled on 160 acres, two miles northwest of El Monte. He was elected County Supervisor in 1876, and served eight years. He also served as deputy assessor and school trustee. Mr. and Mrs. Hannon had six children, Frank, Edward, Vincent, Mary, Charles and Frances. All except Edward are still living, Frank, Vincent and Mary living in Los Angeles, Charles in Alhambra, and Frances in San Gabriel. Mrs. Hannon died in 1908 and Mr. Hannon in 1910.
Source: C. D. Mayon, F. Brow, L. Stoddard, and C. Mudd; El Monte from the Pioneer Days. WPA Project No. N-5740, 1936. In record 19-187072. (California Historical Landmark No. 765: El Monte). On file at the SCCIC, CSU Fullerton.