The Pennsylvania Eta Chapter of Pi Beta Phi at Lafayette College was originally founded as a local sorority, Delta Psi, in 1978. The chapter officially became a Pi Phi chapter on October 4, 1980 and was the first sorority recognized on campus that is still active today. The initial chapter house was located at 225 Reeder Street, where Lafayette students are still living today.

The original principle of Delta Psi was empowerment for women at Lafayette as they promoted the ideas of unity and began the hopes of joining a nationally recognized sorority.  By joining a sorority, the women of Delta Psi would have the opportunity to create connections with women outside of their own group and establish traditions, continuity, and become part of a history built upon truly wonderful values.  Today, the sisters of Pi Beta Phi continue to live by the first core values first established by the 30 incredible women of Delta Psi, as well as the core values of Pi Phi, and enjoy participating in the traditions and celebrations passed down over the years.