Sooner or later, every genealogist hits a brick wall in her research. You seem to be on the right track and then poof! — Great-grandpa Joe's paper trail disappears. Sometimes the key to breaking through that wall is focusing not on your ancestor, but on the place and time he lived. Historic events such as war, mass migration, famine or epidemic often can explain an elusive ancestor's vanishing act — and give you a sense of his trials and triumphs.

Thanks to the Web, putting your kin in historical context has never been easier. Sites maintained by history buffs, restored historic villages and educational institutions are crammed with detailed accounts (many of them firsthand narratives) of everyday life through the centuries. In seconds, you can track down a recipe for Roman honey cakes, read the nation's reaction to the Custer massacre or find plans for a typical Colonial garden.

If you immerse yourself in an era's history, you'll get a feel for your ancestor's daily routine. And that may lead you right to the chink in your brick wall. So what are you waiting for? Log on to these 37 Web sites and step into the past.