During the late 20th century, the university underwent significant academic, structural, and administrative changes as it developed into a major research university. For much of the 19th century, the university consisted of decentralized and separate faculties specializing in Political Science, Philosophy, and Pure Science. In 1979, these faculties were merged into the Graduate School of Arts and Sciences. In 1991, the faculties of Columbia College, the School of General Studies, the Graduate School of Arts and Sciences, the School of the Arts, and the School of Professional Studies were merged into the Faculty of Arts and Sciences, leading to the academic integration and centralized governance of these schools. In 2010, the School of International and Public Affairs, which was previously a part of the Faculty of Arts and Sciences, became an independent faculty.