This year, the Rock celebrates its 50th birthday. A year into construction, the laborers pictured here were hard at work on the library’s roof. By the time of its dedication on November 16, 1964, the building had space for 1.5 million books and 1,044 students. At the dedication ceremony, David Rockefeller, the son of John, class of 1897, said the building provided for “studying with sumptuousness.” And as many students have since learned, it’s also an ideal place for a nap.