The Organization of American Historians (OAH) was founded in 1907 as the Mississippi Valley Historical Association (MVHA) and was headquartered in Lincoln, Nebraska, for nearly half a century. Originally focusing on the history of the Mississippi Valley, the association evolved into the primary organization of specialists in U.S. history. Membership is open to anyone interested in the organization's mission: promoting excellence in the scholarship, teaching, and presentation of American history, and encouraging wide discussion of historical questions and equitable treatment of all practitioners of history.

OAH publishes the OAH Magazine of History (ISSN 0882-228X) — an important classroom tool for teachers — and The Journal of American History (ISSN: 0021-8723) — which for decades has been the leading scholarly journal in the field. Along with its publishing activities, the OAH holds a four-day annual meeting each spring, which features approximately 150 sessions and workshops concerned with scholarly and professional matters of interest to specialists in U.S. history at all levels and in all settings. The event also includes an exhibit hall for companies that display and sell their recent publications in American history. In 2007, the OAH began assisting community college professors, by developing a series of regional annual workshops to provide professional enhancement opportunities and materials for community college professors teaching the survey course.