One month before the bombing of Pearl Harbor, a seaman aboard the USS Arizona, Jay Wesley Young, wrote a letter to his sister thanking her for the birthday cake.

"I really made a pig of myself," he wrote. Thirty days later, both the cake and Young were gone.

The letter is one of 47 million documents now available online through a partnership of the National Archives and Footnote.com. The site, www.footnote.com/wwii, contains 200 terabytes of photographs, enlistment records, and interactive maps relating to World War II. Highlights include a searchable image of the USS Arizona Memorial in Hawaii, 80,000 photographs and nine million "Hero pages" that can be updated by users themselves.

"We’re bringing World War 2 to the Google generation," said James Hastings, Director of Access Programs at the National Archives. About 50 people have worked on the project since it began in 2006, sorting and digitizing millions of records to make them easily available to a generation of Americans unfamiliar with the Dewey decimal system.

The site is truly interactive, allowing users not only to click and control what they see, but also to contribute content. Like other user-generated content sites such as Wikipedia, Footnote.com users can create new entries, add to existing text and upload images. So far, there is no way to upload video or audio. "We’re working on that," said Justin Schroepfer, Marketing Director at Footnote.com.

There is little oversight, leaving the users to edit themselves.

"We’re not the gatekeeper, we ask the community to police that," said Schroepfer. Currently, about one million people visit Footnote.com each month.

"It’s a great example of public and private sectors coming together to preserve these stories," said Russell Wilding, CEO of Footnote.com.

The entire site is free for the rest of the month, but then some document access will require a subscription of $12 per month or $70 per year.

All of the photographs, Heroes pages and the interactive USS Arizona Memorial will remain free of charge to maintain the public service mission of the National Archives.