- It was a celtic tradition
- It most likely came and was introduced here by the Irish.
- It was turnips, not pumpkins that were carved intially.
Some believe it's the celebration of the celtic new year. The end of the old year fell on what is October 30, and the new year started on November 1. October 31, then, was thought to be a day "in limbo" when the laws of nature and physics were suspended, thus the dead could walk the Earth. On this "limbo" day, people were encouraged to act in a chaotic way, and thus young ruffians wandered the streets causing mischief, or begging for food door to door. Maybe that explains something!!
It's also interesting to note that Catholic church celebrates the Feast of All Saints over a three day period which includes Oct.31st.
Have a safe and Happy Halloween !!