Daniel is looking at old photographs and notices that everyone is wearing a hat. On the street, at the beach, at baseball games. Everyone.

He wants to know when that stopped and why.

The hat was doing several jobs at once. It offered protection from the weather. It signaled social position, occupation, and how formally you were dressed. And for a long time it was simply what a respectable person wore in public. Different hats belonged in different social worlds, and what sat on your head could introduce you before you said a word.

The decline happened gradually across the 1950s and 1960s and had no single cause. Enclosed cars meant people spent less time exposed to the elements. Elaborate hairstyles became increasingly important, and hats did not work well on top of them. Clothing became more casual across the board, and the old ...