Henry Holt and Company is an American book publishing company, in New York City. One of the oldest publishers in the United States, it was founded in 1866 by Henry Holt and Frederick Leypoldt.Currently, the company publishes in the fields of American and international fiction, biography, history and politics, science, psychology, and health, as well as books for children's literature. In the US, it operates under Macmillan Publishers.