In the years following the Civil War, Philadelphia's population continued to grow. The population grew from 565,529 in 1860 to 674,022 in 1870. By 1876, the city's population stood at 817,000. The dense population areas were not only growing north and south along the Delaware River, but also moving westward across the Schuylkill River. A large portion of the growth came from immigrants, still mostly Irish and German. In 1870, twenty-seven percent of Philadelphia's population was born outside the United States.