The Gilder Lehrman Institute of American History
From Gilder Lehrman Institute: "The Gilder Lehrman Institute of American History was founded in 1994 by Richard Gilder and Lewis E. Lehrman, visionaries and lifelong supporters of American history education. The Institute is the leading nonprofit organization dedicated to K–12 history education while also serving the general public. Its mission is to promote the knowledge and understanding of American history through educational programs and resources.
At the Institute’s core is the Gilder Lehrman Collection, one of the great archives in American history. Drawing on the 70,000 documents in the Gilder Lehrman Collection and an extensive network of eminent historians, the Institute provides teachers, students, and the general public with direct access to unique primary source materials."