John was born at
Chester Co., South Carolina, in 1833. He was the son of
James Knox Hemphill and
Elizabeth Chestnut Millen. He married
Martha Jane Culp at
Brownsville, Cooper Co., Missouri, on 22 December 1857. John Calvin Hemphill was census 1870 in 1870 at
Blackwater Twp., Saline Co., Missouri; 1870 Missouri, Saline Co., Blackwater Twp. lists the following family:
John C. Hemphill, age 37, born in South Carolina;
Martha J. Hemphill, age 33, born in Kentucky;
Florence E. Hemphill, age 11, born in Missouri;
Henry A. Hemphill, age 10, born in Missouri;
Sulla W. Hemphill, age 8, born in Missouri;
John A. Hemphill, age 6, born in Missouri;
Sallie E. Hemphill, age 4, born in Missouri;
George E. Hemphill, age 2, born in Missouri;
Lucy E. Hemphill, age 1, born in Missouri;
Mary E. Culp, age 15, born in Missouri;
John A. Culp, age 12, born in Missouri. John died in 1901 at
Gainesville, Cooke Co., Texas.