The expression "mad as a hatter" is based on the real-life practices of hatters beginning in the 17th century. It turns out that the process they used to make their hats was poisoning them and ...

He wore it the night he was assassinated. Likely a descendant of the 17th-century steeple, or sugarloaf, hat, which was in turn influenced by the headgear worn by soldiers, the top hat gained in ...