Hunger on campus is part of a lingering national problem that grew after the financial crisis that began in late 2007. In an unforgiving economy, many students across the country struggle not only to pay tuition but also to buy food. Colleges and nonprofit groups have noticed, and more are reacting. Food pantries are cropping up on two-year and four-year campuses nationwide, including, in recent years, at Oregon State University, the University of Georgia, and Valencia College. At Bunker Hill Community College, volunteers from the Greater Boston Food Bank recently gave out truckloads of groceries to needy students. After hearing news reports that students around the country were going hungry, students and campus officials at West Virginia started the Rack in September 2010. In the past two years, campus officials have talked to representatives of more than 20 colleges interested in its model.