USC dropped one spot to No. 24 on U.S. News and World Report National University Rankings on Tuesday night.The publication, which ranks colleges each year on 16 criteria such as fall acceptance rate and graduation rate, released its 2013 rankings at 9 p.m. PDT.USC tied with UCLA — which was previously ranked No. 25 — and the University of Virginia for the No. 24 spot.Harvard University and Princeton University tied for the top spot, with Yale University coming in third. West-coast schools Stanford University and California came in at No. 6 and 21, respectively.All the colleges in the National Universities category on the site offer a variety of undergraduate majors, master’s and Ph.D. programs and place an emphasis on faculty research.