Born on May 10, 1915, in Chester, South Carolina, Hemphill attended the public schools.

Hemphill volunteered in 1941 as a flying cadet in the United States Army Air Corps and served as a bomber pilot until December 1945.

[2] Hemphill was elected as a Democrat to the Eighty-fifth and to the three succeeding Congresses, serving from January 3, 1957, until his resignation May 1, 1964, to take a federal judicial post.

During his Congressional service, he was a delegate to the North Atlantic Treaty Organization Congress in London in 1959.

On that day, Hemphill was reassigned by operation of law to a new seat authorized by 79 Stat.