Born in El Paso, Texas, Callahan attended Wink High School where he played football and basketball, ran track and threw both the discus and the javelin.
[1] After the start of World War II, Callahan had joined the Navy and in August 1943 he was called to duty and transferred to Texas for V-5 pre-flight training.
[1] After finishing his football career and graduating, he worked as a sales manager of a Lubbock car dealership and then at the University of New Mexico in Albuquerque.
[1] After a round of golf in El Paso in March 1978, he suffered a fatal heart attack and died at 57 years old.
[1] In 1999, Odessa American newspaper named him the 20th Century's best high school football player from the Permian Basin.