Peanut butter and jelly. It's as American as apple pie -- perhaps even more so, considering we collectively eat 700 million pounds of peanut butter and about a billion pounds of fruit spreads each year, including jellies, jams and marmalades.
And, although peanut butter's inventor is unknown, by 1895 the Kellogg Co. (yep, the same folks who pioneered Corn Flakes) patented a process for making raw peanuts into a butter-like consistency. No one knows who first thought to combine PB with J, but it's believed it started during World War II when American GIs mixed the two rations to make the peanut butter more palatable. After the war ended and servicemen returned home, sales of the two foods soared.
Now peanut butter and jelly sandwiches are a mainstay of nearly every American kid's diet, which begs the question: Without peanut butter and jelly, what would we do with all those slices of bread?