courtesy www.al.com

On Halloween night costumed ghosts and goblins will knock on doors across the U.S., asking for a treat with the threat of a trick as part of the deal.

Ever wondered why we say "trick or treat?" at Halloween. It turns out the practice draws from a range of traditions.

According to History.com, Halloween traces its roots to the pre-Christian Celtic festival of Samhain, which was celebrated on the night of Oct. 31. The ancient Celts believed the dead returned to earth on Samhain and would celebrate with bonfires and other practices to honor the deceased. Some celebrations involved people dressing up in costumes, often choosing ghosts and demons to act out the parts.

The early Christian church wasn't a fan of the pagan celebration and looked to replace it with its own event, designating Nov. 1 as All Hallows Day or All Saints Day, a time to honor Catholic Saints. The day was celebrated in much the same way, however, with bonfires and masquerades. People would also visit neighbors and receive "treats" in exchange for praying for the souls of their loved ones. In return, the visitors would often tell a joke or perform an act as a "trick."

Early Colonists - many of whom were religious Puritans - didn't celebrate Halloween. Irish immigrants coming to America in the 1840s helped popularize the tradition and it soon spread throughout the U.S. Early celebrations included fireworks, ghost stories and general mischief making. The Irish also brought the tradition of Jack O' Lanterns, carved pumpkin (although they used turnips in Europe) as a way to fend off evil spirits.

The American celebration became intertwined with the English tradition of "guising" when the poor would go around asking for money and before long, young people - and pranksters - were traveling door-to-door in search of treats.

The earliest known use of the words "trick or treat" occurred in 1934 when a Portland, Oregon newspaper ran an article about how local youth had pulled numerous Halloween pranks. The phrase eventually showed up on greeting cards and by the 1940s was in general use on the holiday.

Halloween facts

Here are some Halloween facts from the U.S. Census Bureau:

• There will be an estimated 41.1 million trick-or-treaters - children ages 5 to 14 - hitting the streets tonight in search of treats.
• Some of the best places to spend Halloween: Tombstone, Arizona; Scarville, Iowa; Transylvania County, North Carolina; Yellville, Arkansas; Slaughter Beach, Delaware; and Kill Devil Hills, North Carolina.
• 39,815 - The number of people employed by U.S. manufacturing establishments that produced chocolate and cocoa products in 2015. This industry's value of shipments totaled $17.2 billion, up from $16.0 billion in 2014.
• $12.4 million - The value of U.S. imports of pumpkins in 2016. Pumpkin carving and decorating is a popular Halloween tradition.
• $1 billion - The estimated amount people will spend children's Halloween costumes this year.
• 35 million - The number of pounds of candy corn produced each year.

Did you know?

According to the National Retail Federation, consumers will spend nearly $7 billion on Halloween this year, making it the second-largest commercial holiday in the U.S. behind only Christmas.