More than a quarter of Philadelphians are in desperate need of some brotherly love. With 26.3 percent of its population living below the national poverty line, Philadelphia is the poorest big city in the United States, Philly.com reported in September, and many of those living in poverty are trying to make ends meet without a roof over their head. While nonprofit Project Home said it's difficult to calculate the exact number of residents living on the streets, it estimates 650 people are living without shelter in Philadelphia at any point in time.