They’ve Been In The U.S. Since The 16th Century
The first Amish families came into America in 1693, stemming from a European Anabaptist movement that had been around since 1525. This was founded as a radical separation from the Protestant church and set itself apart with its laws about adult baptism. They also preferred a church free from government interference.
The Amish, named after the religious leader Jakob Ammann, became a separate faction from the traditional Anabaptist movement and eventually fled to America, where they started a colony in Pennsylvania. Although growth was initially slow, they had enjoyed a boom in population in recent years.