In addition to practicing law, Hiscock became involved in politics, initially as an anti-slavery
Democrat, and then as a member of the
Free Soil Party. Hiscock became a
Republican when the party was founded in the 1850s, and served as
district attorney of Onondaga County from 1860 to 1863. He was a member of the State constitutional convention in 1867, elected to fill the vacancy caused by the death of his brother.
In 1872 Hiscock supported
Liberal Republican nominee
Horace Greeley for President, and in 1876 he was a delegate to the
Republican National Convention.
U.S. House of Representatives He was elected as a representative to the
Forty-fifth and to the four succeeding Congresses and served from March 4, 1877, to March 3, 1887. He was chairman of the House Committee on Appropriations in the (
Forty-seventh Congress). He was reelected in 1886 for the term starting March 4, 1887, but resigned in order to accept the U.S. Senate seat to which he had been elected
in January, 1887.
U.S. Senate Hiscock was elected to the
United States Senate by the
New York State Legislature, defeating incumbent
Warner Miller and
Levi P. Morton in the Republican caucus and Democrat
Smith M. Weed in the vote of the full legislature. Hiscock served from March 4, 1887, to March 3, 1893, and was chairman of the Committee on Organization, Conduct, and Expenditures of Executive Departments (
Fifty-first and Fifty-second Congresses). Hiscock was an unsuccessful candidate for reelection. After leaving the Senate, he resumed the practice of law in
Syracuse. ==Death and burial==