Library of Congress Signs Up

Library of Congress Signs Up Library officials explained the agreement Truck Cover Chinaas another step in the library’s embrace of digital media. Twitter, the Silicon Valley start-up, declared it “very exciting that tweets are becoming part of history.”

Academic researchers seem pleased as well. For hundreds of years, they say, the historical record has tended to be somewhat elitist because of its selectivity. In books, magazines and newspapers, they say, it is the prominent and the infamous who are written about most frequently.

But although celebrities like Mr. Kutcher may have the most followers on Twitter, they make up a tiny portion of its millions of users.

“This is an entirely new addition to the historical record, the second-by-second history of ordinary people,” said Fred R. Shapiro, associate librarian and lecturer at the Yale Law School.

The library reached out to the company a few months ago about adding Twitter’s content to the national archives, said Matt Raymond, the library’s director of communications. He cited Twitter’s “immense impact on culture and history,” like its use as a vital communications tool by political dissidents in Iran and Barack Obama’s turning to Twitter to declare victory in the 2008 election.

The Twitter archive will join the ambitious “Web capture” project at the library, begun a decade ago. That effort has assembled Web pages, online news articles and documents, typically concerning significant events like presidential elections and the terrorist attacks of 9/11, Mr. Raymond said.

The Web capture project already has stored 167 terabytesTruck Cover China of digital material, far more than the equivalent of the text of the 21 million books in the library’s collection.