I apologize for not replying sooner.
Kern County is in central California, with the largest city and county seat being Bakersfield.
The Who's Who book lists the date of marriage if it was provided by the bio subject (in this case, Frank Baumgart).
Information about obtaining copies of marriage licenses from Kern County:http://www.co.kern.ca.us/ctyclerk/marriage/ccopy.asp
Here are transcripts of the bios on Frank and Esta Jane:
BAUMGART, Esta Jane Fleming. Parents, John Morris and Hannah Ada (Huber) Fleming. Married, Frank T. Baumgart, Sept. 6, 1925. Born, Lyndon, Kan., Nov. 17, 1891. Educated Elementary and High School, Meridan, Kan. With Crews-Beggs Co., Department Store, millinary department, Pueblo, Colo.; J.B. Smith & Co., Greeley, Colo.; Marvel Millinery, Bakersfield, Calif., from 1918 to 1927. Member: Meridan Chapter O.E.S., charter member; Tehachapi Chapter No. 188, O.E.S.; Tehachapi Study Club; Woman's Club of the Tehachapis; Ladies Aid Society, president; and Tehachapi Community Church, and served as vice president, 1929-30-31 and 32. At various times has been active in this work since 1927 and has served ovvicially since 1929. Came to Kern County in 1924. Recreations: travel and community work. Address: Tehachapi, Calif.
BAUMGART, Frank T. Parents William and Phillippena (Theurer) Baumgart. Born, Danville, Ill., Oct. 25, 1880. Married, Esta Jane Fleming, Sept. 6, 1925. Educated, Elementary schools of Columbus, Nebr., Lewis Institute, Chicago, Ill.; licensed pharmacist in California since 1923. Occupation: Proprietor, Baumgart Electrical Appliance Store, and Co-Owner of Beekay Theater, Tehachapi Calif. He entered the drug business at Danville, Ill., in 1895 and has been active in that field in several states since then. He was with Bear Bros. drug store, Bakersfield, 1924-27. He purchased the Globe Drug Store, Tehachapi, in 1927 and operated that business as Frank T. Baumgart Drug Store until October, 1936, at which time he established the Frank T. Baumgart Electrical Appliances store in Tehachapi, but which operates in Tehachapi and Mojave. He built and opened the Beekay Theater, Tehachapi, in 1936 and has operated this business since then. He is a member of the Tehachapi City Council and has been Mayor of Tehachapi since Jan. 1, 1938. He has been active in the development, building and improvement of Tehachapi since 1927. He was a member of the Tehachapi Chamber of Commerce with which he served officially from 1928 to 1934. Member: Bridgeport, Ill., Lodge No. 386 F. & A. M.; Mississippi Valley Consistory (East St. Louis) Scottish Rite; Al Malakiah Temple of Shrine, Los Angeles; Tehachapi Exchange Club; Board of Trustees, Tehachapi Community Church, and Chairman of the Board since 1930. Recreation: Travel. Address: 106 Green street, Tehachapi, Calif.
Wow! And you didn't even know about Kern County? Hope this makes your genealogical day...