U.S. Route 13 in Pennsylvania in the context of "Market Street (Philadelphia)"

Market Street, originally known as High Street, is a major east–west highway and street in Philadelphia, Pennsylvania, United States. The street is signed as Pennsylvania Route 3 between 38th Street (U.S. Route 13) and 15th Street (PA 611). A short portion of the road continues west from Cobbs Creek Parkway (63rd Street) to Delaware County, adjacent to Philadelphia. The street also serves as the dividing line for the "north" and "south" sides of the city. All north-south addresses in the city start at zero at Market Street.

High Street was the familiar name of the principal street in nearly every English town at the time Philadelphia was founded. But if Philadelphia was indebted to England for the name of High Street, nearly every American town is, in turn, indebted to Philadelphia for its Market Street. Long before the city was laid out or settled, Philadelphia's founder, William Penn, had planned that markets would be held regularly on the 100-foot (30 m) wide High Street.