The video gets off to a bit of a slow start, so I started about 6 minutes into it when she actually gets to the topic at hand. The most interesting bit was the plug for the Burnley and Trowbridge Mantua-Making Workshop which you can check out here.
While I disagree with some of the statements made at the beginning I believe that overall she came up with a good explanation.
A Dress Historian Explains the History of the Witch Hat
