But over the years, the registry has grown to include films that are lesser known but no less important such as the 1956 Puerto Rican short film “Modesta,” about a woman who rebels against her husband. Those responsible for recommendations to the Library of Congress registry are typically film critics, theater owners and film professionals from the Screen Actors Guild and the Directors Guild. This time around, they included the 1934 classic about an actress and the producer who made her a star: “Twentieth Century.” "It’s an example of a film that’s added to the registry because it’s endured," Loughney explained. "It’s always at the top of people’s evaluations and critical lists and again that has an influence on the selection." But, he's quick to add, movie fans get their say, too. And they've been campaigning to include “Forrest Gump” and “Silence of the Lambs" for going on three years. Loughney says even modern films like these deteriorate. But older films made of highly flammable nitrate stock are the most fragile. The Library of Congress estimates three out of four films made between 1912 and 1930 have been lost to fire or neglect...or to opportunists looking to harvest the silver. "It’s a little known fact that by 1920, the Kodak Company was using four tons of silver per week in the manufacture of motion picture and other film products. So that was a real economic incentive to burn film or to recycle it in some way. That caused the loss of many film prints." The Library of Congress is storing more than 145 million feet of nitrate film in its underground facility. It has a fulltime film preservation lab that works to preserve America’s cinematic heritage. For each film on the Registry list, the Library acquires an archival quality copy to add to its enormous library.