Norristown is a municipality (with home rule status) and the county seat of Montgomery County, Pennsylvania in the Philadelphia metropolitan area. Located along the Schuylkill River approximately 6 miles (9.7 km) from the Philadelphia city limits, Norristown has a population of 34,324 as of the 2010 U.S. Census. It is the fourth most populous municipality in the county and second most populous borough in Pennsylvania.
The area where Norristown sits was originally owned by the family of Isaac Norris. Along with William Trent, Norris purchased the land on October 7, 1704 for 50¢ per acre. In 1712, Norris acquired Trent's share and established a gristmill at the foot of present-day Water Street.
Named the county seat in 1784 when Montgomery County was formed, Norristown was incorporated as a borough in 1812 and subsequently enlarged in 1853. About 500 people lived there at the time of its incorporation. Growing rapidly after the Civil War, it swelled to 22,265 people by 1900. By 1940 it was home to 38,181 Norristonians, making it the most populous borough in Pennsylvania before declining in the decades after World War II, and in fact it was described in that year as "the most populous independent borough in the United States."
At its height, Norristown was an industrial, retail, banking, and government center. Breweries, cigar factories, textile mills, icehouses, foundries, rolling mills, and lumber yards provided ample employment for skilled laborers and artisans. The downtown featured two department stores, several theaters, and enough goods and services that residents never had to leave town to find anything they needed.