It was early June, still too soon for the summer influx of beachgoers and holidaymakers, when I visited America’s most famous pond. The only people besides photographer Tim Laman and me were a few hardy swimmers, wetsuited against the cold, and a lone sculler taking in the morning freshness. Walden had the air of solitude its resident thinker, Henry David Thoreau, so greatly prized—despite the hum of commuter traffic through the trees.

We made a circuit of the pond looking for wildflowers to photograph, and Tim was rewarded with a photogenic pair of pink lady’s slipper orchids not far from the walking path. I peeked through the windows of the replica of Thoreau’s cabin in the woods with its three chairs—“one