From Ohio History Central
Postcard of the Main Building of Heidelberg College, Tiffin, Ohio.
During the 1500s, John Calvin and Ulrich Zwingli established the German Reformed Church in Switzerland. The church was formed in the midst of the Protestant Reformation. It was one of several denominations created in opposition to the Roman Catholic Church.
The first Members of the German Reformed Church came to North America in the 1720s. German, Swiss, Dutch, and French immigrants formed dozens of German Reformed Churches in North America, especially in the British colonies of Pennsylvania, New Jersey, and New York. In 1793, the leaders of the German Reformed Church in the United States severed ties with the church leadership in Europe and established the Synod of the Reformed Church in the United States. In 1869, the German Reformed Church formally became known as the Reformed Church in the United States. In 1942, this body of churches united with the Evangelical Synod of North America and officially became known as the Evangelical and Reformed Church. In 1957, this new religious organization joined with the Congregational Church to establish the United Church of Christ.
The German Reformed Church had a strong influence in Ohio in the 1800's. In 1850, at least seventy-four German Reformed Churches existed in the state. The German Reformed Church also established Heidelberg College in Tiffin, Ohio.