During most of his adult life he preferred to be called G. William Barnum.
He was killed, together with his wife Julia and their daughter Mary in the head on collision of their car with a heavy truck near Fayetteville, Arkansas. The Rev. and Mrs. Barnum were killed instantly and their daughter died later in a hospital. The accident happened when the car the Rev. Barnum was driving collided with a 2 ½ ton truck driven by Marvin W. Wells of Belleville, Arkansas. The accident occurred about 13 miles south of Fayetteville.
From the Yell County Record, Danville, Arkansas, 2 March 1961: Three Die In Car-Truck Wreck. A retired minister, his wife and their daughter died Saturday after their compact car collided head-on with a truck near Fayetteville. Rev. G. William Barnum, about 70, and his wife, about 65, were killed instantly. Miss Mary L. Barnum, 39, died about three hours later in a Fayetteville Hospital.
Barnum's car collided with a truck driven by Marvin Wells, 25, of Belleville on a curve near West Fork, 13 miles south of Fayetteville on Highway 71. The accident happened about 7 a.m. Wells, a driver for the Joe Ray Poultry Co. of Danville, was driving a truck loaded with empty egg cases. He was treated for shock in a Fayetteville hospital and released Sunday.