Horatio King was born in 1811 in Paris, Maine. He worked in the printing office of the Jeffersonian and ultimately bought the weekly newspaper in 1831 with future vice-presidential candidate Hannibal Hamlin. Six months later, Hamlin sold his shares to King, who used the paper to promote Jacksonian policies.

King sold the paper in 1838 and began a career in the federal post office department that would last for over two decades. He worked first as a clerk and then was put in charge of securing mail contracts in New England. In 1850, he became superintendent of the Foreign Mail Service and was an integral player in the 1853 Bremen Convention, which established cheaper rates for international postage.

In 1854, King served as first assistant postmaster general before becoming postmaster himself in 1861, during the administration of President James Buchanan. King served for only about a month before Abraham Lincoln was inaugurated as President of the United States. Though Lincoln appointed his own postmaster general, he retained King’s services and appointed him to a committee addressing compensation rates for emancipated slaves in the District of Columbia.

King spent the remainder of his life working as a lawyer and an author. He died in 1897.