Ambedkar was a prolific student, earning doctorates in economics from both Columbia University and the London School of Economics, and gained a reputation as a scholar for his research in law, economics and political science. In his early career he was an economist, professor, and lawyer. His later life was marked by his political activities; he became involved in campaigning and negotiations for India's independence, publishing journals, advocating political rights and social freedom for Dalits, and contributing significantly to the establishment of the state of India. In 1956 he converted to Buddhism, initiating mass conversions of Dalits.