Allentown, the county seat of Lehigh County, is located 50 miles north-northwest of Philadelphia on the Lehigh River. It is connected on the east with Bethlehem and along with Bethlehem and Easton constitutes a metropolitan area. Allentown is in an area of limestone deposits, from which developed the cement industry for which the city is known. The surrounding agricultural area is part of the Pennsylvania Dutch region. The land on which Allentown later developed was obtained from Thomas Penn, son of William Penn, the founder of Pennsylvania. In 1745, it was purchased by William Allen, a Philadelphia merchant. Allen built a private lodge on the site but the town itself did not begin to develop until the 1760's. At first it was named Northhampton, as was the county around it. In 1770, William Allen's son James Allen built Trout Hall, which is now a museum. The community was incorporated as a borough in 1811 and became the county seat of newly formed Lehigh County the following year. In 1838, the name was changed to Allentown in honor of its founder. Allentown Seminary opened its doors in 1848, changing its name to Muhlenberg College in 1867. Lehigh was given city status in 1867.