Jefferson Duo / Pennsylvania Triad

The Jefferson Duo is the name given to two fraternities founded at Jefferson College in Canonsburg, Pennsylvania. Jefferson College is now Washington and Jefferson College in Washington, PA. The two fraternities that make up the Jefferson Duo are Phi Gamma Delta and Phi Kappa Psi.

Phi Gamma Delta, also known as Phi Gam or Fiji, was founded on May 1, 1848. Fiji does not use the term "alumni" for its post-collegiate members, but rather "graduate brothers," implying that membership extends far beyond the undergraduate experience. Phi Gamma Delta also has limitations on where chapters and members can display its Greek letters. The fraternity's letters are considered sacred and are never displayed on an object that can be easily destroyed. In place of the actual Greek letters, "Fiji," "Phi Gam," or the English spelling of "Phi Gamma Delta" are used in their place.

Phi Kappa Psi was founded on February 19, 1852. The fraternity was formed after an illness struck some of the student body and two students teamed up to care for their fellow classmates. A brotherly bond was developed among these dedicated young men which led to the formation of Phi Kappa Psi. The fraternity's maxim is "The Great Joy of Serving Others." Phi Kappa Psi has over 70,000 alumni, its official charity is the Boys and Girls Club of America, and its colors are cardinal red and hunter green.

The term Pennsylvania Triad is created when the duo is grouped with Phi Kappa Sigma Fraternity, which was founded on October 19, 1850, at the University of Pennsylvania.

Phi Kappa Sigma was founded by Dr. Samuel Brown Wylie Mitchell at UPenn who recorded the initial ideas and concepts. He was later joined by six students who became the seven founders of the fraternity that is also known as Skulls, Skullhouse, Phi Kap, and PKS.