John Gardner Shinkle was born in
Boston, Massachusetts, on 10 March 1912, the son of Edward Marsh Shinkle, a
West Point graduate of the class of 1901, and his wife Margery née Gibbons. He was appointed to West Point from the 6th District of Ohio, the same one his father had been appointed from, and entered on 1 July 1929. He graduated 23rd in the class of 1933 on 13 June 1933, and was commissioned as a
second lieutenant in the
Field Artillery Branch. Shinkle's first posting was to the
76th Field Artillery Regiment, which was based at the
Presidio of Monterey, California. There he met and married Emily Harris, whose father, Henry Leavenworth Harris Jr. graduated from West Point with the class of 1899, grandfather Henry Leavenworth Harris graduated with the class of 1869, and great-grandfather N. Sayre Harris with the class of 1825. He acquired a stepdaughter, Suzanne, from her first marriage. They had two more children: a daughter, Miriam, and a son, John Michael, Promoted to
first lieutenant on 13 June 1936, Shinkle was posted to the
13th Field Artillery Regiment at
Schofield Barracks in the
Territory of Hawaii. He was seconded to the
Ordnance Department on 12 March 1937, and became the ordnance officer of the
18th Composite Wing at
Fort Shafter in the Territory of Hawaii. He returned to the United States on 9 May 1938, and attended the Ordnance School at
Watertown Arsenal in Massachusetts. He underwent training at the
Picatinny Arsenal in New Jersey, and the
Aberdeen Proving Ground in Maryland, where he became a proof officer for arms and ammunition. He also earned a master's degree in mechanical engineering from the
Massachusetts Institute of Technology in 1939. ==World War II==