While U.S. Grows, Historic Cities Shrink

"Phoenix has overtaken Philadelphia as the nation's fifth largest city, underscoring decades of population losses in America's big industrial centers.

The nation's population has nearly doubled since 1950 _ adding about 150 million people. But of the 20 largest cities at mid-century, all but four have shrunk, some by a lot.

Detroit, Cleveland, Pittsburgh, St. Louis and Buffalo, N.Y., have all lost more than half their population in the past half-century."

"Phoenix was barely in the top 100 cities in 1950 _ it ranked 99th, with about 107,000 people. Last year, it had 1.5 million.

Phoenix added 43,000 people from 2005 to 2006, more than any other city, according to the Census Bureau estimates. It was followed by San Antonio; Fort Worth, Texas; Houston; and North Las Vegas, Nev."

"Americans have been migrating south and west for decades in search of better job opportunities and warmer climates. They have also been moving to the suburbs and beyond, in search of bigger yards and houses, lower crime rates and better schools."