The Presbyterian Church in the United States of America (PCUSA) was a Presbyterian denomination existing from 1789 to 1958. In that year, the PCUSA merged with the United Presbyterian Church of North America. The new church was named the United Presbyterian Church in the United States of America. It was a predecessor to the contemporary Presbyterian Church (USA).
The denomination originated in colonial times when members of the Church of Scotland and Presbyterians from Ireland first immigrated to America. After the American Revolution, the PCUSA was organized in Philadelphia to provide national leadership for Presbyterians in the new nation. In 1861, Presbyterians in the Southern United States split from the denomination because of disputes over slavery, politics, and theology precipitated by the American Civil War. They established the Presbyterian Church in the United States, often called the "Southern Presbyterian Church". The PCUSA, in turn, was described as the Northern Presbyterian Church. Despite the PCUSA's designation as a "Northern church", it was once again a national denomination in its later years.