Once, when I visited my brother, who lives in a small Texas town, he took me down a winding road to a turn-of-the-20th-century cemetery in a forest clearing. There, we found three tall tombstones in the shape of tree trunks, each stamped with an insignia reading “Woodmen of the World.” What were these strange things?

When I got home, I dug into the mystery of these stone stumps, discovering the profoundly insecure time before Americans had Social Security, when anxieties about …