Ambridge is a borough in Beaver County in Western Pennsylvania, incorporated in 1905 and named after the American Bridge Company. Ambridge is located 16 miles (25 km) northwest of Pittsburgh, alongside the Ohio River. In 1910, 5,205 people lived in Ambridge; in 1920, 12,730 people lived there, and in 1940, 18,968 people resided in Ambridge. The population was 7,769 at the 2000 census.
The town is near the location of Legionville, the training camp for General "Mad" Anthony Wayne's Legion of the United States. Wayne's was the first attempt to provide basic training for regular U.S. Army recruits and Legionville was the first facility established expressly for this purpose.
The Harmony Society first settled the area in the early 19th century, founding the village of "Ökonomie" or Economy in 1824. Although initially successful, accumulating significant landholdings, the sect went into decline. By the end of the 19th century, only a few Harmonists remained. The Society was dissolved and its vast real estate holdings sold, much of it to the American Bridge Company, who subsequently enlarged the town and incorporated it as Ambridge in 1905.