Lancaster County was established on May 10, 1729. Formed from part of Chester County, it was one of the original three PA counties. Lancaster was Pennsylvania’s “first western county,” and became a prototype for the 64 counties to follow. The early Mennonite and Amish settlements in the region date back to 1525, but it was not until 1683 that William Penn purchased the land from the Indians. The tract extended from the Delaware to the Susquehanna Rivers, and it was from this tract that both Chester and Lancaster counties were ultimately established. Indian history came to an end in Lancaster County in 1763 when a gang known as the Paxtang Boys broke into the local jail and murdered the last members of the Conestoga Indian Tribe. These Native American men, women and children had been placed in the jail to protect them from those gangs. Part of the old jail is still visible as part of the Fulton Opera House in Lancaster.