Over the past three centuries American Jews have committed themselves to numerous political and social causes. During the nineteenth century, American Jews were deeply divided over the question of slavery and succession, on both sides of the Mason-Dixon line. Jews also took part in domestic politics and, at the same time, they established a variety of organizations that worked on behalf of oppressed Jews in other parts of the world. By participating in twentieth century causes such as the Civil Rights Movement and the efforts to help Jews living in the former Soviet Union, many American Jews became convinced that by defending the rights of others who were oppressed and downtrodden, they were in fact safeguarding their own civil liberties.