Lawrence S. Barker, Jr. was born on January 15, 1920 in Chattanooga, Tennessee. Barker held a degree in civil engineering from the University of Tennessee. He enlisted in the United States Marine Corps Reserve on January 10, 1942 and reported for active duty as a Private First Class in Quantico, Virginia in September of that year. Barker was commissioned as a Second Lieutenant in December 1942 and stayed in the Reserve Officer Class until early March of 1943, when he was ordered to Camp Lejeune, North Carolina as an Engineer Officer Instructor in surveying and mapping.

Barker was promoted to Lieutenant in August 1943 and was subsequently ordered to New Zealand to join the 2nd Marine Division. Barker participated in the four-day battle of Tarawa in the Pacific on November 20-23, 1943. He then spent time in Hilo, Hawaii before sailing (via Pearl Harbor) to Eniwetok Atoll on May 21, 1944. Barker then proceeded to Saipan on June 15, 1945, where his division suffered many casualties. His division also spent time on the island of Tinian.

Barker's division landed in Okinawa on April 1, 1945. In Okinawa, Japanese Kamikaze bombers destroyed several ships. Barker was later transported back to Saipan, where he prepared maps for the invasion of Japan, termed the "Olympic Operation" by military officials. During this time, atomic bombs were dropped on Hiroshima and Nagasaki and the division began preparing new maps to meet the needs of an occupation instead of an invasion. Barker landed in Nagasaki in September 1945 and began surface and aerial surveys to map the damage caused by the atomic bomb.

Barker was promoted to Captain in November 1945 and landed back in the United States on December 24, 1945. He was released from active duty on January 30, 1946 and moved into inactive reserves in April of 1946. Barker was promoted to Major in April 1951 and retired in 1964. Lawrence S. Barker passed away on September 20, 1994 in Knoxville, TN.