Phil S. Gibson participant of World War I
Early life and education
Gibson was born in Grant City, Missouri on November 28, 1888. He was the son of William Jesse and Mollie (Huntsman) Gibson. He attended the University of Missouri, graduating in 1912 with an A.B. and in 1914 with a LL.B.  During college, he served as the secretary to the school's athletic director, Chester Brewer.In June 1914, on his graduation from law school he formed a partnership with David H. Robertson in Mexico, Missouri, and in November 1914 he was elected the Prosecuting Attorney of Worth County, Missouri. In April 1918, during World War I, Gibson was commissioned a Lieutenant in the 137th Infantry of the American Expeditionary Force, and later that year was posted to the front. After the war, he studied at the Inns of Court in London. Discharged from the service in 1920, he joined his brother in Denver, Colorado, and practiced law for two years.