Candy-coated popcorns date to the mid-1800s.
Compare this recipe to the recipe for “Nicodemus Pop-Corn” from The Household (of the Detroit Free Press): A Cyclopaedia of Practical Hints for Modern Homes. That recipe calls for boiling the sugar until it starts to thicken, but not for caramelizing it.
The immediate next recipe for popcorn balls calls for adding molasses. At some point, someone realized caramelizing the sugar produced molasses-like results with a sweeter finish, because by the 1930s, caramel corn was sold on street-corners.
From the box of L.S. from Joplin, Missouri.
Oven Caramel Corn
2 cups brown sugar
2 sticks oleo
1/2 cup white syrup
1 t. salt
1/2 t. soda
12 cups popped corn
Combine sugar, oleo, syrup, and salt.
Boil 5 minutes.
Stir in soda. Pour immediately over popcorn.
Bake 1 hour and stir every 15 minutes at 200 deg.
Put on cookie sheet to cool. Stir to keep from sticking.