John Jefferson King, lawyer and politician, the son of John and Virginia (Ship) King, was born in Franklin Parish, Louisiana, on July 26, 1863. His prominent and wealthy family was devastated by the Civil War; his father was a former member of the governor's staff, and his mother was descended from early settlers of Jamestown, Virginia. Late in 1863 the family moved to Bowie County, Texas, where King was educated in the public schools.
He served as deputy district and county clerk in 1883–84 and then began to study law on his own. He was admitted to the bar on December 10, 1885, and elected county attorney in 1886 and 1888. In 1890 he was elected representative from Bowie, Cass, Marion, and Morris counties to the Twenty-second Legislature. In the House he was made chairman of the House Committee on Engrossed Bills, a high honor for a first-term representative. After his term in the legislature he was elected county judge of Bowie County in 1892 and again in 1894.
King retired from politics in 1897 and began to practice law in Texarkana. In 1899, with Hiram Glass and William Lee Estes, he formed the law firm of Glass, Estes, and King. The firm, later named Glass, Estes, King, and Burford (with the addition of A. L. Burford), was one of the most prominent corporate law firms in the state; it served as general attorney for some of the largest railroad companies in Texas. In the 1920s it was dissolved after Glass died, Estes was appointed to a United States judgeship, and Burford became general attorney for the Louisiana and Arkansas Railroad. King then became senior member of the law firm King, Mehaffey, and Wheeler.
He was a director of Texarkana National Bank, first vice president and director of the Texarkana and Fort Smith Railway Company, vice president of the Port Arthur Canal and Dock Company, trustee of the William Buchanan Foundation, and a member of the boards of the local chapters of the chamber of commerce, United Charities, and Community Chest. He was a Mason, a Democrat, and a Presbyterian. On March 18, 1894, he married Caroline A. Wise of Barton, Texas. The couple had two children. King died on February 6, 1940, and was buried in Texarkana.