Once an once important battlefront during the American Revolution, this area sits atop a high rock escarpment above the city where the air often seems purer. In the 19th century the area was home to high-minded institutions such as the Leake and Watts Orphanage, the Bloomingdale Asylum, a home for the aged, and other institutions. Served only by horsecars, the city seemed to be reaching the borders of the Heights in the last quarter of the 19th century, giving rise to a spate of Episcopalian related institutions which sought to create America's new pantheon of good will organizations. Developers pushed north from the Upper West Side and built fine apartment houses along Riverside Drive in the early 20th century. Riverside Park and the Columbia campus provided greened and open spaces for the streets surrounding the university.