The members of a North American Anabaptist Christian sect that originated in Europe in the 17th century as followers of Jakob Ammann, a Mennonite bishop whose teachings caused controversy and schism in the 1690's among the Mennonites in Switzerland, Alsace, and southern Germany. Ammann insisted that any Mennonite who had been excommunicated should be ostracized by all other Mennonites and that anyone who told a falsehood should be excommunicated. He taught that church members should dress in a uniform manner, that beards should not be trimmed, and that it was wrong to attend services in a state church. Amish settlements and congregations were started in Switzerland, Alsace, Germany, Russia, and Holland, but migration to North America in the 19th and 20th centuries and assimilation with Mennonite groups gradually eliminated the Amish in Europe.

Around 1720, the Amish began migrating to North America and first settled in southeast Pennsylvania, where a large settlement is still found. Because of tensions between traditional Amish and progressive Amish, during the next fifty years about two-thirds of the Amish either formed small, independent churches or joined either the Mennonite Church or the General Conference Mennonite Church. Those who continue the Amish lifestyle are primarily members of the Old Order Amish Mennonite Church.

The largest Amish settlements are located in Pennsylvania, Ohio, Delaware, Indiana, Iowa, Illinois, and Kansas. The settlements are divided into church districts that are autonomous congregations composed of about seventy-five baptized members. Because they meet in each other's homes, the district is divided if it becomes much larger. There are no church buildings. Each district has a bishop, two to four preachers, and an elder.

The Amish differ little from the Mennonites in formal doctrine. Holy Communion is celebrated twice each year, and washing of feet is also practiced. Adults are baptized when they are admitted to formal membership in the church at about age eighteen. Services are conducted in what is commonly known as Pennsylvania Dutch.

The Amish are best known for their plain dress and plain living. Amman proscribed shaving and the use of buttons as "worldly conformity." The men wear broadbrimmed black hats, beards, but do not have mustaches. Homemade plain clothes are fastened with hooks and eyes instead of buttons. The women wear bonnets, long full dresses with capes over the shoulders, shawls, and black shoes and stockings. No jewelry of any kind is worn. The Amish also shun telephones and electric lights and drive horses and buggies rather than automobiles. The Amish are self-sufficient and are excellent farmers, although they often refuse to use modern farm machinery. Children attend public elementary schools but are not sent to high schools. This practice has caused the Amish some difficulty because of compulsory school attendance laws, and some Amish parents have gone to jail rather than allow their children to go to high school.