The Orthodox Presbyterian Church was founded in 1936, largely through the efforts of John Gresham Machen. Machen and others had founded Westminster Theological Seminary in 1929, in response to a re-organization of Princeton Theological Seminary. In 1933, Machen, concerned about Liberal Christianity|liberal theology tolerated by Presbyterians on the mission field, formed the Independent Board for Presbyterian Foreign Missions. The next Presbyterian General Assembly reaffirmed that Independent Board was unconstitutional and gave the associated clergy an ultimatum to break their links. When Machen and seven other clergy refused, they were suspended from the Presbyterian ministry.