Presbyterians trace their history to the sixteenth century and the Protestant Reformation. Presbyterian heritage, and much of what they believe, began with the French lawyer John Calvin (1509-1564), whose writings solidated much of the Reformed thinking that came before him.
Calvin did most of his writing from Geneva, Switzerland. From there, the Reformed movement spread to other part of Europe. Many of the early Presbyterians in America came from England, Scotland and Ireland. The first American Presbytery was organized at Philadelphia in 1706. The first General Assembly was held in the same city in 1789. The Assembly was convened by the Rev. John Witherspoon, the only Christian minister to sign the Declaration of Independence.
The Presbyterian Church (USA) currently is struggling with a major division over Biblical interpretation, particularly as it relates to homosexuality. Current policy prohibits the ordination of practicing homosexuals; the policy was upheld by a vote of presbyteries in 2002. Practicing homosexuals remain welcome as members, although - at least officially - they can't serve as pastors or serve as elders on the church sessions (the equivalent of a local board of directors). They are also prohibited from becoming deacons.