During the latter half of the 20th century, Washington University transitioned from a strong regional university to a national research institution. In 1957, planning began for the construction of the “South 40,” a complex of modern residential halls. With the additional on-campus housing, Washington University, which had been predominantly a “streetcar college” of commuter students, began to attract a more national pool of applicants. By 1964, over two-thirds of incoming students came from outside the St. Louis area.