Well it all depends...

You Know You're in a Southern Sorority House When...
Credit: Duane Howell/Getty Images

Figuring out which sorority can lay claim to being the first is a surprisingly complex topic that goes way back through the history of Greek organizations in the United States. Town & Country recently took a deep dive into the topic and the story is fascinating.

Most people agree that Pi Beta Phi was the world's first sorority of sorts, gracing the world with its existence in 1867 at Monmouth College. However, when they were founded, they were called I. C. Sorosis, and Pi Beta Phi was merely their motto. They were the first women's Greek organization to expand to different chapters, when they opened a branch at Iowa Wesleyan College in 1868. It wasn't until 1888 that they officially switched their name to the Greek letters. Pi Beta Phi then went on to become one of the seven founding members of the National Panhellenic Conference, in 1902. While their long history should give them the title of world's oldest sorority, Pi Beta Phi never actually used the word "sorority" and didn't start with a Greek name, which some people consider a strike against their claim.

The first group to be founded using Greek letters was Kappa Alpha Theta who were organized in January 1870 at Indiana Asbury (now DePauw University), according to this fascinating history of fraternities and sororities in the U.S. There's no disputing the fact that they were the first Greek letter society for women as well as the first group to expand internationally by setting up a chapter at The University of Toronto in 1887, but Kappa Alpha Theta never called themselves a "sorority" per se, so some people aren't sure they count as the first either.

WATCH: 12 Things All Southern Sorority Girls Know

It wasn't until 1874, that the word "sorority" was used to describe Gamma Phi Beta, the new Greek organization for women at Syracuse University. According to Town & Country, the term came from a male Latin professor who dubbed the group of women a "sorority," which means sisterhood. The Gamma Phi Beta's loved the name and soon adopted the title officially and became the first Greek-letter organization to call themselves "sorority." That could earn them the crown, too, but for the sake of sisterhood, perhaps these three illustrious organizations should share the honor.