Some of the nation's greatest military heroes are also listed. Paul Revere, whose famous 1775 midnight ride informed listeners, "The British are coming!" may be found in the Revolutionary War Service Records, and the records set entitled the Massachusetts Soldiers and Sailors in the War of the Revolution.
Theodore Roosevelt, the only U.S. President to receive the Medal of Honor — the country's highest military honor — is also included.
Smolenyak said a surprising number of women, who served as nurses and in other capacities, are in the database.
"If you had adventurous great aunts, you might want to investigate their military connections," she said.
Retired U.S. Senator and former astronaut Jake Garn served as a Navy pilot and as Brigadier General of the Utah Air National Guard. He said the online records provide families with "precious links that can often be found no where else."
He added, "Through the digitization and online availability of these documents, Americans can discover the story of our nation and remember the military legacies of their ancestors through details such as names, service dates and locations, battles fought, medals or honors awarded and even sometimes, very distinct physical descriptions."
The online collection will be available for free to Internet users from now until the anniversary of D-Day, June 6th, at www.ancestry.com/military.