The Know Nothing Party in his congressional district nominated Hill (without his solicitation) to run for the United States House of Representatives from Georgia in 1857, and it was under that banner that he was elected.

[2][3] He was re-elected to a second term in 1859, but resigned on January 23, 1861, shortly after the state convention passed an ordinance of secession in Georgia.

[1] During the later stages of the Civil War, Hill lost his only son during the Atlanta Campaign in fighting near Lithonia, Georgia.

[1] While Sherman agreed, the portion of his troops passing through Madison were under the command of subordinate General Henry Warner Slocum.

[1] Following the end of the Civil War, Hill was elected to the United States Senate from Georgia as a Republican in 1867.