Horace Cayton was born a slave, the son of a slave and a slavemaster's daughter. After emancipation his father sent all his children to school. Cayton attended Alcorn College, where he studied with United States Senator Hiram Revels, for seven years.
Upon arriving in Seattle in 1886, he became a political reporter for the Post-Intelligencer (and was a supporter of the Republican Party).
In May 1894, he began publishing the Republican. He was assisted in this enterprise by his wife, the writer Susan Revels Cayton.