The American Historical Association (AHA) is the oldest professional association of historians in the United States and the largest such organization in the world. Founded in 1884, the AHA works to protect academic freedom, develop professional standards, and support scholarship and innovative teaching. It publishes The American Historical Review four times a year, with scholarly articles and book reviews. The AHA is the major organization for historians working in the United States, while the Organization of American Historians is the major organization for historians who study and teach about the United States.