A national U.S. Army archive is being digitized, allowing people to click through a treasure trove of U.S. military history online.

It's a huge U.S. Army archive, and more and more of it is accessible online. But in the opinion of those running it, not enough people know about it in the west. 

"Only in the last 10 to 15 years have we become well known as an organization, but mostly in the eastern United States," said John Giblin, chief of visitor and education services for the U.S. Army Heritage and Education Center in Carlisle, Penn.

The archive has four million pieces, ranging from photographs from the Civil War to letters signed by George Washington, to the drama of D-Day. It includes films, videos, and recorded lectures by Army leaders and historians.

Its web page lists the library and archives, events, exhibits, a page for past online lectures, and information about visiting the site which has a museum.

The archive was founded in 1968 in support of the U.S. Army War College. It does not contain Army personnel records, as that falls under the national archives, but a search might find the name of a relative or another person available in its records.

About 10 percent of the vast and growing amount of materials are online, but more is coming, said Giblin. 

"We are beginning a mass digitization project in the next two years that will dramatically increase what we have online," Giblin said.

That said, it's still overwhelming.

"Even if we stopped collecting today, it would take 40 man hours to digitize it all," Giblin said.

But even if it's not digitized, the archives said it can digitize it for you and email you short of a visit.  Fees can range from as little as a dollar for a photocopy, to $35 for high resolution copies. Dubbing of videos can start at $65 for the first hour of a production. 

Related: Full schedule of fees