He was born in Shreveport as the son of a printer who owned E.M. McGregor Printing Company. James delivered milk in summer and worked at a grocery store as a teenager. He graduated from Byrd High School in 1941, studied at Centenary College, and then joined the Navy Reserves in November of 1942. He was called up for active duty on July 1, 1943, was commissioned in June of 1944, and was sent to West Coast Sound School in San Diego. One day on liberty, James and a friend enjoyed sailing on a boat with Humphrey Bogart and Lauren Bacall. Lieutenant McGregor was sent to the Pacific as a gunnery officer aboard USS PC 1260, a vessel in anti-submarine warfare and a sixty-five-man crew. It also escorted larger ships to islands such as Kwajalein, Eniwetok, Guam, Saipan, Tinian, and Iwo Jima. To ease the boredom of shipboard life and to sweeten meals, James scrounged a movie projector and an "ice cream maker." One onerous duty was censoring enlisted men's mail. "That wasn't any fun," he remarks. He returned to America in June of 1946 and later graduated from Centenary College in May of 1947. He became an oil and gas lease broker and remains in the oil industry.