Top hats are a tall, wide brim hat with a flat crown that sits several inches above the base of the hat. Top hats gained popularity at the very end of the 18th century when they began to supersede the then popular tri-cornered hat in popularity. During the height of their popularity everyone from the working middle class to the highest of upper-class wore top hats; with the differentiation being the material that the hat was constructed out of. Inexpensive top hats were made out of rabbit fur whereas expensive top hats were made of felted beaver fur. It wasn't until the mid-19th century that top hats switched to a silk construction instead of fur.
Over the years there have been several different popular styles of top hats though the basic requirements of a flat crown and wide brim have remained unchanged. Two of the most common style variations include the Wellington which had concave sides and the chimney pot which had convex sides. However neither of these were as popular as the stovepipe hat which had completely vertical sides and was popularized by American president Abraham Lincoln. During a brief period of time the folding top hat, the Gibus, gained popularity for wear at the opera or evening events. These top hats utilized a mechanical spring mechanism to facilitate the folding and unfolding action.
Today the top hat is not often worn outside of extremely formal dress occasions and costumed events. Today the top hat is also often times associated with magicians.