NEW YORK—Earlier this week, Dr. Fauci told CNN’s State of the Union that he thinks Halloween 2021 is a go. “I think that, particularly if you're vaccinated, you can get out there and enjoy it,” he said, referring to trick-or-treating for kids, and Halloween parties for adults.  Last year, Halloween celebrations were muted, with fewer parties and fewer trick-or-treaters all around—and while there’s nothing wrong with a cozy, spooky Halloween at home celebrated with a scary movie marathon, there’s something special about knowing we can get back out there this year and spread the Halloween joy.

In celebration of a return of one of the U.S.’s most unique holidays (no one celebrates Halloween quite like Americans do, really), this weekend we’re looking at the history of Halloween, and some fun Halloween facts that you can share in the coming weeks. 

Perhaps unsurprisingly, the history of Halloween as we know it is a little hazy, but it’s likely the ancestor of Samhain, a Celtic festival in which people light bonfires and wear costumes to ward off ghosts, History reports. Samhain is often referred to as an “ancient celebration,” but lots of people around the world still observe it today. 

Pope Gregory III, who served as Pope from February 731 AD until his death in November 741, designated November 1 as All Saints Day, a day for Catholics to honor saints. Many Christian and Pagan traditions melded together over the centuries, and Halloween and All Saints Day provide a perfect example—by 1000 AD, the Catholic Church tacked All Souls Day onto the celebrations. Celebrated on November 2, All Souls Day is a day to honor the dead, and is believed to be an attempt to “replace the Celtic festival of the dead with a related, church-sanctioned holiday,” History reports. 

When pilgrims came to what we now call the United States, they wouldn’t have brought many celebrations with them—they were strict Puritans, after all. However, as World History Encyclopedia reports, they may have continued to observe Guy Fawkes Day—celebrated on November 5 in Britain, in honor of the failed assassination of King James I. Guy Fawkes Day is also called Bonfire Night, and is celebrated with bonfires and fireworks. Eventually, as the United States was established as a nation and more and more immigrants arrived—particularly from Ireland—Samhain, All Saints Day and All Souls Day came with them.

History reports that colonial American Halloween celebrations included telling ghost stories and “play parties,” put together to celebrate the harvest. These celebrations, which included sharing stories of the dead, telling fortunes, dancing and singing may have been a result of contact with Native Americans, too.

It wasn’t until the 1920s and ‘30s that Halloween truly became a secular, nationwide holiday, and there was resistance to it. Vandalism was apparently common on Halloween, and, eventually trick-or-treating was seen as a way to both celebrate the holiday with neighbors and prevent kids from vandalizing your home or community spaces. Merriam-Webster reports that the first uses of trick-or-treat were in in the early 1920s, particularly in the Canadian provinces of Alberta and Saskatchewan. The first U.S. example popped up in 1928, in the Bay City Times in Michigan. 

Today, Halloween as we know it is a uniquely American holiday, relatively divorced from its ancient history. Despite the many changes to the holiday, Pagans around the world still celebrate Samhain, while many Christians also still celebrate All Saints Day and All Souls Day the traditional ways. No matter what your preference, spooky or sweet, there are countless ways to celebrate Halloween and to make the holiday your own.