Pleasanton was originally the county seat in 1858, when settlers, afraid of Native American attacks, relocated the first seat from Amphion (now a ghost town). Named after early settler John Pleasant, the town became a gathering place in the late 1800s for cowboys driving cattle to Kansas. Pleasanton celebrates its ranching heritage each summer with bull riding, music and food at the Cowboy Homecoming. The Longhorn Museum retraces the development of Atascosa County.