I see conflicting #'s for various years on the interweb, Forbes ranks Philly in the top 12 most visited U.S. cities. (July2007)
I have no idea why (nothing against Texas) Dallas & Houston rank higher.
27.7 million (2005); 10.2 million rooms sold; score: 1.86
The City of Brotherly Love’s siren songs include national landmarks like the Liberty Bell Center and Independence Hall. And Philadelphia’s allure is growing for international travelers: The Pennsylvania metropolis was one of only three of the top 20 cities in the United States that has shown an increase in overseas visitation from 2000 to 2005, according to the U.S. Department of Commerce.
The below link ranks Philadelphia as the 3rd most historical city however Philadelphia and Boston are practically equal in my opinion.