King was elected inspector of levees and president of the board of school directors of his district and also a trustee of the University of the South.
King was elected as a Democrat to the Forty-sixth and to the three succeeding Congresses (March 4, 1879-March 3, 1887). He served as chairman of the Committee on Levees and Improvements of the Mississippi River (Forty-eighth and Forty-ninth Congresses). He was an unsuccessful candidate for renomination in 1886. He engaged in mining operations, with residence in Washington, D.C.. Assistant Register of the United States Treasury from May 19, 1914, until his death in Washington, D.C., May 8, 1915. He was interred in Arlington National Cemetery.