Hitchcock was appointed a United States Marshal from 1861 to 1864; a Republican, elected as the Nebraska Territory Delegate to the Thirty-ninth Congress and served from March 4, 1865 to March 1, 1867, when the Territory was admitted as a State into the Union. He was appointed surveyor general of Nebraska and Iowa from 1867 to 1869. In 1870, Hitchcock was elected as a Republican to the United States Senate and served from March 4, 1871, to March 3, 1877. He was an unsuccessful candidate for reelection.