History of Congregationalism
The history of the first Congregationalists begins in the English Reformation. There both Puritans and Separatists of the 17th century attempted to reform the church.
The most famous of the Separatists became the Pilgrims of the Mayflower. Arriving in America in 1620, they established the Plymouth Colony and held their first Thanksgiving in 1621. The Pilgrims who settled to the north of Boston just a few years later became the second group of American Congregationalists.
In American History Congregationalists are known for their interest in an educated clergy. For that reason they founded Harvard College. Later, colleges such as Dartmouth, Olivet and Oberlin were organized by their efforts. They opened Mt. Holyoke, the first institution of higher learning for women in America. Congregationalists were among the first to ordain women in the ministries. Early participation in the Abolitionist Movement called them to develop the Anti-Slavery Society and to found many traditionally black colleges in the South.
You can learn more about the history of Congregationalism on the web page of the National Association of Congregational Christian Churches.