Jack Lummus was born on October 22, 1915, in Ennis County, Texas. He graduated from Texas Military College in May 1937, and then attended Baylor University where he played football and baseball from 1937 to 1941. Lummus enlisted in the U.S. Army Air Corps on May 26, 1941, and began flight training at Hicks Field, Texas, in July 1941, but washed out of flight training and was discharged in August 1941. He then joined the New York Giants and played in the NFL Championship Game in December 1941 before enlisting in the U.S. Marine Corps on January 30, 1942. After completing basic training in San Diego, California, he served as a military policeman at Mare Island, California, from May to October 1942, followed by Officer Training School at Quantico, Virginia. Lummus was commissioned a 2d Lt in the Marine Corps on December 18, 1942, and then served with the Marine Raiders at Camp Pendleton, California, from December 1942 to January 1944. Lt Lummus then served as executive officer of Company F, 2nd Battalion, 27th Marines of the 5th Marine Division, from January to August 1944, and then at Camp Tarawa, Hawaii, from August 1944 until February 1945. He went ashore with the first wave of Marines at Iwo Jima on D-Day, February 19, 1945. After serving as an artillery spotter, he commanded the 3rd Rifle Platoon for Company E from March 6 until he was killed in action two days later on March 8, 1945. Lt Lummus was originally buried in the Fifth Division Cemetery on Iwo Jima, but was later moved to Myrtle Cemetery in Ennis, Texas.

His Medal of Honor Citation reads:

For conspicuous gallantry and intrepidity at the risk of his life above and beyond the call of duty as leader of a Rifle Platoon attached to the 2d Battalion, 27th Marines, 5th Marine Division, in action against enemy Japanese forces on Iwo Jima in the Volcano Islands, 8 March 1945. Resuming his assault tactics with bold decision after fighting without respite for 2 days and nights, 1st Lt. Lummus slowly advanced his platoon against an enemy deeply entrenched in a network of mutually supporting positions. Suddenly halted by a terrific concentration of hostile fire, he unhesitatingly moved forward of his front lines in an effort to neutralize the Japanese position. Although knocked to the ground when an enemy grenade exploded close by, he immediately recovered himself and, again moving forward despite the intensified barrage, quickly located, attacked, and destroyed the occupied emplacement. Instantly taken under fire by the garrison of a supporting pillbox and further assailed by the slashing fury of hostile rifle fire, he fell under the impact of a second enemy grenade but, courageously disregarding painful shoulder wounds, staunchly continued his heroic 1-man assault and charged the second pillbox, annihilating all the occupants. Subsequently returning to his platoon position, he fearlessly traversed his lines under fire, encouraging his men to advance and directing the fire of supporting tanks against other stubbornly holding Japanese emplacements. Held up again by a devastating barrage, he again moved into the open, rushed a third heavily fortified installation and killed the defending troops. Determined to crush all resistance, he led his men indomitably, personally attacking foxholes and spider traps with his carbine and systematically reducing the fanatic opposition until, stepping on a land mine, he sustained fatal wounds. By his outstanding valor, skilled tactics, and tenacious perseverance in the face of overwhelming odds, 1st Lt. Lummus had inspired his stouthearted marines to continue the relentless drive northward, thereby contributing materially to the success of his regimental mission. His dauntless leadership and unwavering devotion to duty throughout sustain and enhance the highest traditions of the U.S. Naval Service. He gallantly gave his life in the service of his country.