Harper

Harper is an American publishing house, the flagship imprint of global publisher HarperCollins, based in New York City. Founded in New York in 1817 by James Harper and his brother John, the company operated as J. & J. Harper until 1833, when it changed its name to Harper & Brothers, reflecting the inclusion of Joseph and Fletcher Harper. Harper began publishing Harper's Magazine, Harper's Weekly, and other periodicals beginning in the 1850s. From 1962 to 1990, the company was known as Harper & Row after its merger with Row, Peterson & Company. Harper & Row was purchased in 1987 by News Corporation and combined with William Collins, Sons, its United Kingdom counterpart, in 1990 to form HarperCollins, although the Harper name has been used in its place since 2007.

From the Wikipedia article “Harper (publisher)”, licensed under CC BY-SA 4.0.

An imprint is a brand inside a larger publishing house, often with its own editors and list. Imprints of large groups usually acquire through literary agents; read recent titles to see whether your book fits the list, then target agents who sell to it.