John M. Jenkins was born in South Carolina in 1863 during the Civil War. He graduated from the U.S. Military Academy (USMA) in 1887 and served on frontier duty for several years. During the Spanish American War he participated in the capture of Puerto Rico (1898). He served as an instructor at the South Carolina Military Academy (1893-97) and later at the U.S. Military Academy (1900-04) while Douglas MacArthur was a cadet.
