The Organization of American Historians (OAH), known prior to 1966 as the Mississippi Valley Historical Association, founded in 1907, is the largest professional society dedicated to the teaching and study of American history. OAH's members in the U.S. and abroad include college and university professors; historians, students; precollegiate teachers; archivists, museum curators, and other public historians; and a variety of scholars employed in government and the private sector. The OAH publishes the Journal of American History, the OAH Magazine of History. Among its various programs, OAH conducts an annual meeting each spring, and has a robust roster on its OAH Distinguished Lecturership Program.

More information on the Wikipedia page [1]

The website is [2].