Ballston Spa is a village in Saratoga County, New York, United States. The population was 5,556 at the 2000 census. It is the county seat of Saratoga County. The village is named after Rev. Eliphalet Ball, a Congregationalist clergyman and an early settler. The village lies on the border of two towns and is partly in the Town of Ballston and partly in the Town of Milton. The village is southwest of Saratoga Springs.HistoryThe village was first settled in 1771. In 1787 Benajah Douglas, father of 1860 presidential candidate Stephen A. Douglas, built the first tavern and hotel at Ballston Spa. It was located near the natural spring.In 1803 Ballston Spa's Sans Souci Hotel, at the time the largest hotel in the United States, was built by Nicholas Low. Presidents, senators and governors stayed there, as well as many wealthy private citizens. Ballston Spa was incorporated as a village in 1807.At one time the village was served by four railroads: the Delaware and Hudson Railway, the Ballston Terminal Railroad, the Schenectady Railway Company, and the Hudson Valley Railway.