The history of Halloween can teach us how traditions of people travel across the earth. 

Historians are people who study old stuff and write history books to tell us what happened before the time we are living in now.

Many historians think that Halloween started as a tradition of the Celts (a group of people who lived around Ireland about 2,000 years ago).

At the end of summer, the Celts thought the barrier between our world and the world of ghosts and spirits got really thin.

This meant they thought weird creatures with strange powers could wander about on Earth.

The Celts had a big party. It was all about scaring away the ghosts and spirits.

Later on, people of the Christian religion turned the date into "All Hallow's Eve," or "All Saint's Day," which was a day to honor really great people who had died.

Poor people in Ireland would disguise themselves on this day and go door to door asking for food in exchange for prayers for the dead.

Does that sound a bit like trick-or-treating??

Many years later, around the 1800s, people from Ireland started to immigrate to America, which means they left their country and moved to ours.

Here in America, we turned the ancient tradition into a SUPER-FUN AND EXCITING HOLIDAY for kids and adults to enjoy every year!!!

"All Hallow's Eve" became "Halloween", and we got lots of candy and decorations because of it!