Historical markers like this one in Adelphi, Md., are dedicated to locally famous people rather than places or events.  Mother Jones, as you see, was a labor organizer

If you travel across America, especially old two-lane highways and backroads, you'll pass little roadside signs called historic markers. These are certainly not great monuments to epic moments in American history. Nor are they much to look at. Usually they're simple plaques or small metal tablets stuck on a post, containing brief descriptions of events that are often obscure to everyone except local history buffs.

Yet lots of travelers — the sort who are in no particular hurry and like to absorb a little local color — pull over, stretch their legs, and take a look at these signs.

Chisled stone historical markers are somewhat rare.  This one talks about a time capsule, buried in Mulbury, Fla., in 1977 and scheduled for unearthing in 2076

And now an Internet Web site is building a list, descriptions, and photographs of as many of these markers as travelers tell them about. Hundreds and hundreds of them.

As the Webmaster of the site, called The Historical Marker Database, writes, "[t]he richness of history is in its local details. . . . History is not just about the high and mighty."

Sometimes historical markers are simple plaques, like this one in Lake Havasu City, Ariz., that describes the move and reassembly of the London Bridge there in 1971

So the site, which is divided into what seem like a hundred categories and is also arranged by state, takes us to places like Stringfellow Orchards in Texas, where a marker tells all about the history of horticulture in the state. To a spot in Florida where the first Christian cross was planted in the New World. And to a place in Nebraska where, from 1837 to 1850, more than a quarter-million buffalo-skin robes bought from Native Americans were hauled over the trail between forts Pierre and Laramie.

And here's the bridge itself, which was crumbling and could no longer handle traffic across the Thames River.  So it became a U.S. tourist attraction instead

In many places, you won't see the actual caves and gold mines, settlers' cabins and frontier saloons to which the historical markers refer. But people stop anyway and exercise their imaginations instead.

The Historical Marker Database can be found at http://www.hmdb.org/