The following is from a work-in-progress about the history of Fullerton. You can support my ongoing research and writing on Patreon.
Arthur Staley was born near Santa Rosa, California in 1870, a son of Theodore and Drusilla (Teague) Staley, the former a native of Missouri, and the latter of Indiana.
“Both parents were pioneers of California,” biographer Samuel Armor wrote in 1921. “Theodore Staley having crossed the plains with ox-teams in 1856, and Drusilla Teague was brought on the long overland journey by her parents in 1865, the wagons being drawn by horses, and some trouble with Indians was encountered by the young pioneers.”
Theodore Staley farmed in Sonoma County until 1881, when he moved to Orange, and then Placentia, growing grapes, oranges, and walnuts. He was active in county politics, serving on the Democratic County Central Committee and as a school trustee.
Theodore and Drusilla Staley had three children: Arthur, Myrtle, and Walter. Theodore died in 1903 in Placentia.
Arthur Staley attended grammar school in Placentia and was one of the first graduates of the newly-formed Fullerton high school. He graduated from Stanford University in 1900.
He worked various jobs in agriculture and banking. He was secretary of the Fullerton Walnut Growers Association, and the Placentia Orange Growers Association.
He worked for the Farmers and Merchants Bank of Fullerton, and also as a director of the Yorba Linda Water Company, and the Placentia National Bank.
His wife was Bessie Pendleton.
In addition to his other business interests, Arthur owned a 25-acre orange grove in Yorba Linda, which he planted in 1910.
He was active in the Fullerton Masonic Lodge.
Here is a 1906 promotional advertisement for Fullerton that appeared in Out West magazine. Arthur Staley is listed as a local banker.

Source:
History of Orange County, California: with biographical sketches of the leading men and women of the county who have been identified with its earliest growth and development from the early days to the present by Samuel Armor. Los Angeles Historic Record Co, 1921.