Phoenix population passes Philadelphia

PHILADELPHIA, May 18 (UPI) -- A University of Pennsylvania demographer has determined that the population of Phoenix, Ariz., has overtaken Philadelphia's 1.45 million people.

Phoenix is now the 5th-largest U.S. city, pushing Philadelphia into sixth place, the Philadelphia Inquirer reported.

Philadelphia was the nation's 3rd-largest city in terms of population in 1950. It fell to 4th place in 1960 and to 5th place in 1990.

University of Pennsylvania urban studies professor Janice Fanning Madden projected that Phoenix overtook Philadelphia Monday, based on U.S. Census data.

While Philadelphia has been limited to 135 square miles for more than a century, Phoenix has expanded from 247 square miles in 1970 to 565 square miles today.