George Crum invented what popular food item?

He invented potato chips

http://www.enchantedlearning.com/inventors/page/p/potatochip.shtml

You bagged it, Jenny !
The story, possibly apocyrphal, has Crum, a Mohican, the Chef in Saratoga Springs,NY, where Commodore Vanderbilt was known to frequent. Vanderbilt complained his fried potatoes were too thick, so hotel chef George Crum decided to get the last laugh on the Commodore by shaving his next batch of potatoes razor thin. The resulting potato chips were a hit with Vanderbilt as well as many other diners. I do know that the Crum and Potato Chip portions are true. I am not too sure about the Commodore.