He read law and was admitted to the South Carolina Bar in 1875 at the age of nineteen, although he had not finished college.
Following his admittance to the bar, King entered private practice in Atlanta, Georgia and began a series of jobs serving as legal counsel to various railroad companies. Foreign the Atlanta & West Point Railroad, he took the position of assistant general counsel (1887–1893), simultaneously serving as general counsel for the East & West Railroad of Alabama (1887–1889), and again as assistant general counsel to the Richmond and Danville Railroad and Richmond and West Point Terminal Railway and Warehouse Company, from 1890–1892. Lastly, King represented the Chattanooga, Rome and Columbus Railroad from 1894–1901.
In 1912, King was appointed to the United States. Court of Appeals, 5th Circuit, as a committee member to report on revision in equity in United States. courts.
He also served on the board of directors, and as one term chairman, of the Georgia State Bar Examiners from 1913–1918. In 1916, King received a civil law degree from The University of the South, in Sewanee, Tennessee.
In November, 1918, President Woodrow Wilson appointed King to serve as Solicitor General. With his breadth of knowledge of railroad legislation, he was a valuable asset to the administration, contributing his expertise when faced with cases involving the Southern Pacific Railroad throughout 1919.
During this time he also served as legal counsel for the American Red Cross.
On April 29, 1920, President Wilson nominated King to the seat on the United States Court of Appeals for the Fifth Circuit that had been vacated by Don Albert Pardee. King was confirmed by the United States Senate on May 24, 1920, and received his commission the same day. After his judicial appointment, King resigned from his position as Solicitor General.
King died soon thereafter, in Flat Rock, North Carolina.
Member of the board State Bar Examiners, 1913-1918 (chairman).
Married Alice May Fowler, July 13, 1881. Children: Edward, Alexander C.