The Presbyterian Church (U.S.A.), with denominational offices in Louisville, Kentucky, has approximately 2.3 million members, more than 10,000 congregations and 14,000 ordained and active ministers. Presbyterians trace their history to the 16th century and the Protestant Reformation. Our heritage, and much of what we believe, began with John Calvin (1509-1564), whose writings crystallized much of the Reformed thinking that came before him.