Phi Rho Sigma Society (ΦΡΣ) is a co-educational medical fraternity founded by medical students at Northwestern University in 1890.

Phi Rho Sigma Medical Fraternity was founded at the Chicago Medical College (now Northwestern University Feinberg School of Medicine) on October 31, 1890.^[1][2] Its founder was Milbank Johnson, along with, H. H. Forline, J. A. Poling, and T. J. Robeson.^[2] Johnson became the fraternity's first president and designed its badge.^[3]

The fraternity expanded to include Beta chapter at the University of Illinois in the fall of 1894 and Gamma chapter at the University of Chicago in the fall of 1895.^[2][4] Alpha chapter offer saw the general affairs of the fraternity until 1896 when a grand chapter was formed.^[2] The grand chapter consisted of three members from each chapter who were elected annually. The grand chapter could issue charters and enact laws.^[2]

In response to the addition of new chapters, the fraternity adopted a revised constitution on March 20, 1899, which specified that the grand chapter would meet biennially and would consist of two delegates from each chapter.^[2] Its first general convention was held in Chicago on July 3, 1899 through July 5, 1899.^[2] Conventions have been held as of 1920 biennially.^[5] Between conventions, the executive power of the fraternity is vested in a grand council composed of seven members who all reside in the same vicinity.^[5]

The fraternity's periodical, Phi Rho Sigma Journal, began in January 1900.^[2][6] Its first editor was Dr. T. B. Swartz of the Alpha chapter; he served in this capacity for four years.^[7] The Iota chapter also published a magazine called The Iota for many years.^[8]

At the grand chapter meeting in July 1901, the constitution was amended to allow alumni chapters.^[9] The Chicago Alumni chapter was chartered on November 5, 1901.^[10] Its founders were Dr. E. W. Andrews, Dr. Charles M. Gleason, Dr. Frank Jay, Dr. Mortimer Frank, and Dr. D. E. W. Wenstrand.^[10]

At the grand council meeting of February 20, 1908, the various chapters were divided into districts that were overseen by district managers.^[11] The five districts included Eastern (Lambda), Erie (Kappa, Nu, Phi, Rho, Sigma, Skull and Septre, Upislon, and Zeta), Chicago (Alpha, Beta, Gamma, Omicron, and Pi), Mississippi (Eta, Theta, Iota, Mu, and Tau), and Pacific (Delta).^[11]

On April 17, 1911, Phi Rho Sigma absorbed Alpha Omega Delta, a former national fraternity that had a remaining chapter at the University of Buffalo.^[12] The new chapter was allowed to keep the name Alpha Omega Delta because of its history.^[12]

On April 6, 1929, the authorities of Chi Zeta Chi Fraternity signed an agreement in Cincinnati to merge into Phi Rho Sigma. By 1936, the fraternity had 27 active collegiate chapters and eighteen alumni chapters.^[1] At the time, its membership had grown to 19,050 members.^[1]

In 1960, the grand chapter established national awards in the form of gold medals that are given at the biennial meeting.^[13]

• The Irving S. Cutter Medal is awarded to members for extraordinary service to the field of medicine.^[13]
• The Jesse Ansley Griffin Medal is presented to members for outstanding service to society.^[13] The medal was named for the founder of Chi Zeta Chi.
• The Paul McLain Student Research Award is given to student members for significant research while in medical school.^[13] McLain was a physician and scientist dedicated his life to teaching medical students.^[13] This award comes with a medal and a cash award.^[13] Recipients also present their research at the grand chapter.^[13]
• Certificates of Meritorious Service are also awarded by the grand chapter.^[5]

In 1973, the fraternity changed its name to Phi Rho Sigma Medical Society and started accepting women as members.^[14]

Phi Rho Sigma's colors are gold and scarlet.^[2][5] Its badge was originally a gold shield with the letters Φ, Ρ and Σ in black enamel, surrounding a raised pair of clasped hands in gold over an open book in gold. The Φ was in the upper left-hand corner, the Ρ in the upper right-hand corner, and the Σ below at the apex of the shield.

At the grand chapter meeting on December 2, 1896, the badge was updated to a monogram design submitted by Gamma chapter.^[15] The modified badge consists of the letters Φ, Ρ, and Σ as a gold monogram outline, with Φ on a separate plane above the other two letters, set in pearls.^[5]

• Chi Zeta Chi
• Professional fraternities and sororities