I tried to look up Kenneth Jackson but there were too many around the same birth year without knowing where he was born.
Kenneth Jackson Born Abt: 1913 Spouse: Northa C. Zeller Age: 47 Marriage: 24 June 1966, Monterey Co., CA Source: California Marriage Index 1960-1985.
Their marriage license may or may not say where he was born. You can ask what info is on 1966 era records before you order a copy from the Monterey County Recorder-County Clerk, www.co.monterey.ca.us/recorder/ .
Kenneth Jackson Born: 23 July 1912 POSSIBLE Last Residence: Stockton, San Joaquin, California Died: 14 Feb 2009 Soc. Sec. # assigned in Pennsylvania before 1951. Source: Social Security Death Index.
I'd look for his obituary and Northa's in San Joaquin Co. There is an obituary volunteer at geneasearch.com/lookups/ca.htm Scroll down and look for San Joaquin County, California in bold print
If that doesn't work out, contact the Stockton-San Joaquin County Public Library, www.stockton.lib.ca.us/ . Successful Searching!