Many things were not Jack-o-lanterns. Anything that isn't a
pumpkin, turnip, or rutabaga was not used to make jack-o-lanterns.
There is not a lot of other material to make one with either.
Jack-o-Lanterns were originally made from turnips.
What is the popular food used to carve jack-o-lantern?
Pumpkins are used to carve jack-o-lanterns.
Out of what were jack-o-lanterns originally made?
Jack-o-Lanterns were originally made from turnips.
What were used as jack o' lanterns before pumpkins?
turnips
Where did the use jack o' lanterns originate?
That ultimately depends on how you use a Jack-O-Lantern.
Most commonly, Jack-O-Lanterns are used on Halloween as a spooky
or silly head of a false person. For the origin of this tradition,
see the related question "Where did the tradition of carving
pumpkins into Jack-O-Lanterns originate?".
Why are the vegtable lanterns called jack o lanterns?
Because the worlds famous Jack O Lantern died and everybody puts the jack o lanterns in there window sell so that it reminds people about Jack O Lantern.