Born on May 2, 1910, in Atlanta, Georgia, Bonnyman's family moved to Knoxville, Tennessee. His father was the president of Knoxville's Blue Diamond Coal Company. He attended Princeton University where he studied engineering and played football. During his sophomore year, he joined the U. S. Army Air Corps and began flight training in June 1932 but washed out three months later. Afterwards, he worked in the coal industry then moved to New Mexico and started a copper mining business.
At the start of the Pacific War, Bonnyman was exempt from military obligation due to his age and because his company produced a vital material for the war effort. Regardless, he enlisted in the U.S. Marine Corps (USMC) as a private in Phoenix, AZ and was trained at the Marine Corps Recruit Depot in San Diego, CA.
Assigned to the 2nd Battalion, 8th Marines, 2nd Marine Division. In October 1942, Bonnyman embarked on SS Matsonia and participated in combat on Guadalcanal as part of a pioneer unit. In February 1943, he received a battlefield commission as a second lieutenant due to his leadership skills.
On November 20, 1943 Bonnyman led a demolition team during the assault on Tarawa (Betio). While pinned down near Betio Pier, he led attacks that overcame enemy installations. The next day he led an assault on a bunker which contained approximately 150 Japanese soldiers. While attacking on November 22, 1943 he was mortally wounded and died. He was buried in a field burial on the island that was forgotten and lost.
Medal of Honor
Posthumously, he earned the Medal of Honor. In 1947, the medal was presented to his family by Secretary of the Navy James Forrestal with his daughter, Frances, accepted the medal on behalf of the family.
Recovery of Remains
In June 2015, Bonnyman's remains, along with the remains of 35 other Marines who were killed in action, were located and recovered by History Flight / Mark Noah on Betio. His remains will be transported to Defense POW/MIA Accounting Agency (DPAA) / CILHI in July and returned to the family by August 2015.