>My understanding was that it depended upon the type of establishment, what you were trying to do there, and if there was a place to put your hat. I *think* the convention existed because men wore a lot of oil and wax in their hair at the time, so it was to stop their hair getting wet or dirt sticking to the oil. Any indoor environment that was likely to be as dirty as the street (like a factory or a train station) they wore a hat. Anywhere it wasn't (like a doctor's office or a church) hat came off. It's also a hygiene issue: Why would you want your hat, which is covered in rainwater, street dirt and pigeondroppings hovering over everyone's food and such. Taking it off in clean places is polite, same with taking off your overcoat. Only jews continued to wear their hats in clean places. >Weirdly, women were not ever really expected to remove their hats, and wearing hats indoors was considered dressing up for them. Women were allowed to wear fashion statement hats even in court...reminds me of how our pal Hulk Hogan had to get special permission from the judge in modern times to wear his signature bandanna in court. Yeah, that's true come to think of it. Women were less likely to do dirty jobs like men and they used umbrellas in the rain, so their fancy hats weren't really a hygiene issue.