June 5, 1837
On June 5, 1837, the Presbyterian Church in the United States of America voted to rescind the 1801 Plan of Union with Congregationalists. That action labeled four New School Presbyterian synods brought in by the 1801 plan “to be out of the ecclesiastical connection of the Presbyterian Church of the United States of America.” The result was to split the church into Old School (primarily mid-Atlantic and Southern churches) and New School divisions (primarily New York, New England and mid-west churches). The differences focused on theology, polity, and social reform (reflecting Presbyterian differences on slavery). This 32-year split ended in 1869 when the two factions reunited. In the intervening period, Southern churches had split from the Old School Presbyterian Church (USA) at the beginning of the Civil War.