I have no idea who these people are. I found the photo on the sidewalk, picked it up out of curiosity, and haven’t been able to throw it away.

I don’t know their names, but I think I know a bit about them. They are Dad and the kids, squirming and squinting while Mom snaps the picture. They’re sitting on the marble steps of the Lincoln Memorial, facing east toward the Washington Monument and the Capitol dome. Judging from their clothes, it’s summer, about 25 years ago. They are on vacation.

Here’s what I wonder: Do these children—wherever they are, whatever they’ve become—do they remember this trip? Did it change them, or change the world for them, in any way?

Asked when and how they first got interested in preservation, lots of people answer that it began in childhood, with trips to restored plantations, forts, and presidential birthplaces. When I hear that, I always feel that I missed out. During my own childhood, family vacations took us either to East Texas, where we visited relatives, or to Colorado or New Mexico, where we looked at mountains. History played no part in our travel plans.

My first intimation of the connection between history and place didn’t come until much later, when I moved to Richmond, Virginia. By then, I had been a history buff for many years, and in Richmond, for the first time in my life, I was confronted with tangible elements of the history that up to then had existed for me only in books. It was a life-changing revelation.

One morning I drove out to the battlefield at Beaver Dam Creek, the site of fierce fighting during the Seven Days campaign that raged around Richmond in the summer of 1862. I stood there with a guidebook in my hand… and I could see it. Right here—right next to this mound where I was standing—were the Union trenches. And over there was the hillside where the Confederates had charged out of the woods, running down the slope to the creek, firing their rifles and yelling in the summer heat. I could see it all. It was real.

Another day I went to St. Paul’s Church downtown and, after a few minutes of searching, found the pew I was looking for. I sat in it and thought: This is where Jefferson Davis was sitting on that Sunday morning in 1865 when someone crept in and told him that Petersburg had fallen and Richmond was doomed. Right in this building. Here on this very spot.

The fact that I could see and walk through these places, could touch the nicks and grooves where history had bumped against them, impressed me enormously. It still does. In fact, the more I think about it, the more I’m convinced that this is one of the most important reasons why we choose to preserve old buildings and neighborhoods: These places permit us to have tactile encounters with the past. History stops being just an idea, a scrap of story, or a page in a book, and is transformed into a thing with texture and solidity—a brick wall, an iron railing, a pane of glass, a grassy trench, a church pew. Something you can connect with. Something you can touch.