Appointed: 1868 -1871
James Null Walker was born on February 7, 1829, in DeSoto, Missouri to William G. and Elizabeth Null Walker. In March of 1850, Walker, his brother Charles, and an uncle left Jefferson County, Missouri for California. The Walkers traveled by wagon train to Salt Lake City.
From Salt Lake City, they made their own way to Humboldt County, Nevada. The Walkers left Nevada for Gold Rush country where they quickly realized their fortunes were not in the gold fields.
The Walker brothers arrived in Mariposa County in the fall of 1851. James and Charles were successful merchants at the Coarse Gold Gulch from 1852 until 1859. When the gold mines were depleted in 1860, J.N. Walker moved to Fine Gold Gulch, where he opened a small store and engaged in ranching. In 1863 and again in 1871, Walker was elected Assemblyman for Fresno County. In 1867, Walker established his 1,200-acre ranch on the north side of the San Joaquin River in what is now Madera County. Walker, aged 87 years, died in Fresno on Saturday, January 22, 1916. He was survived by his wife and six children.
J.N. Walker was elected Sheriff – Tax Collector of Fresno County in 1867, and served two terms. The hotly contested election of 1867 between candidate Walker and the incumbent J. Scott Ashman has been passed down through time as a major event in early Fresno County history. The widespread partisan feelings were uncompromising in speech and demeanor. Charles P. Converse, builder of the new courthouse and jail, was a vocal supporter of Walker. While the votes were being counted, an Ashman partisan, John Dwyer threw a cobblestone at Converse's head, narrowly missing. Converse immediately fired at him with his gun, and missed. Converse was set upon by another assailant, W.H. Crowe, who wielding a slung-shot, struck a severe blow to the back of Converse's head. Converse was dazed, but quickly arose, and fired at the fleeing assailant W.H. Crowe who ended up face down in the street. Converse whirled about seeking other threats, and fired once more, knocking the hat off the head of John Dwyer. Converse was disarmed and delivered to the jail to be the first inmate housed in the county's new jail; Converse was acquitted at trial.
Sheriff Walker served the people of Fresno County well. Walker was deemed a fair, conscientious enforcer of the law. He pursued, captured, and brought to justice the many murderers, livestock rustlers and robbers he had sought.