Ancestry.com is celebrating the website’s 15th anniversary with 15 days of free genealogy databases and giveaways.

A new database will be free each day, and stay free through Oct. 15. So far, you can search for free:

• Social Security Death Index (also free elsewhere online, including FamilySearch and RootsWeb)
• Griffith’s Valuation, 1848-1864, an important resource for Ireland
• California Marriage Index, 1960-1985
• WWI Personnel Rosters, 1914–1918, from Bavaria, Germany (records are in German)
• 1920 US Census
• Australian Electoral Rolls, 1903–1954

You also can enter to win daily prizes from Ancestry.com, culminating in a grand prize trip behind the scenes of the NBC show “Who Do You Think You Are?“

Go here to see Ancestry.com’s daily free databases and enter the sweepstakes.