One summer day in 1939 a young man stopped another man under an elevated train in New York City and asked him, “Do rich people and poor people have anything in common?” The man replied, “God made all this, and he made it for everybody. And he made it equal. This breeze and these green leaves out here is for everybody.…This breeze comes from God and mancain’t do nothing about it.” The younger man would have many more conversations like that one, and with all the voices ringing in his head, he eventually sat down and wrote a sprawling love song to America’s complexity and paradox that he called Invisible Man .

Ralph Ellison was one of hundreds of young, government-funded writers, editors, researchers, and photographers who fanned out across the nation during the 1930s. TheFederal Writers’ Project (FWP) produced 275 books, 700 pamphlets, and 340“issuances” (articles, leaflets, and radio scripts). The manuscripts, containing thousands of raw interviews, photographs, and notes, were put in storage at the Library of Congress after the project ended in 1943. And the writers—among them Studs Terkel, Zora Neale Hurston, and Saul Bellow—moved on.

In the mid-1970s the library began reorganizing the FWP materials and transferring them back to the library, where nearly 300,000 items are now available to the public. But you don’t have to travel to Washington to use them. The National Digital Library has culled 2,900 interviews for a Web site called American Life Histories ( www.memory.loc.gov/ammem/wpaintro/wpahome.html ). With pictures by photographers like Gordon Parks and Marion Post Wolcott, you can read the interviews and listen to the subjects’ voices.

So, if you want to know why Clyde (“Kingfish”) Smith started singing while he worked, visit “Hard Times in the City: Testifying.” To learn how Mr. Garavelli’s lungs survived stone cutting, see “All in a Day’s Work: Industrial Lore.” Soon you will see why that young man under the elevated train fell in love with language—the American language.