Sidney Phillips was born September 2, 1924. His father, a teacher who became principal of Murphy High School in Mobile during the War, had been a 2nd lieutenant in the 145th Infantry in World War One, and had been wounded in the Argonne Forest. Phillips' best friend growing up was Eugene B. Sledge.
Phillips graduated from high school in June of 1941 and went to work with the U.S. Engineers, carrying maps between departments while saving for college. On December 8, 1941, he was just seventeen when he and a friend enlisted in the Marines. After training, Phillips was assigned to H Company, 2nd Battalion, 1st Marines Regiment, 1st Marine Division, and taught to operate the 81 mm mortar.
In the spring of 1942 he went overseas -- first to New Zealand, and then, in August, to the Solomon Islands where he participated in the landings on Guadalcanal.