Brims started getting skinnier as the decade progressed. Crowns started becoming more tapered and shorter. Towards the end of the decade, "stingy brim" hats started appearing, which will be discussed more in the 1960s section. Remember that none of these changes occurred with the change in decade, that it was a fluid change over the years. Some manufacturers held on to older styles for longer, and a manufacturer would probably be producing hats for a younger market and a more conservative market at the same time.
For the most part, brims shank down to somewhere in the 2 inch region, though in some cases it was much less. You do see hats with brims greater than 2-1/4", but they are not the majority they once were. Ribbons grew proportionately wider. Crowns lowered and tapered.
The welt edge seems to have overtaken other edge finishes.
Extreme Stingy brim
More conservative style.
Dinerman, Excellent documentation. Very interesting. Thanks for posting it.
Great thread, Spencer. Thanks for documenting all this information.
Domingo, ponte el sombrero y vamos.