From its founding in the 17th century through the early 19th century, the City of Philadelphia was considered the area between the Delaware and Schuylkill Rivers and between Vine and South Streets. Although the city proper was second to New York City in population at the time of the first U.S. Census in 1790, Philadelphia County was the most populous urban (or metropolitan) area in the nation until 1810, when it was surpassed by New York. In 1854, the Act of Consolidation incorporated the rest of Philadelphia County and created Philadelphia's modern border. This resulted in a large population increase, evident in the 1860 census.