[1] It was founded in 1879 at Russell Military Academy in New Haven, Connecticut as the Society of Kappa Psi.

While these two early units failed, another chapter formed at Hillhouse Academy of New Haven, Connecticut in 1894.

[3] However, the founders of these chapters, many having graduated and entered college, sought a collegiate level re-establishment of the order.

A third group of advancing students formed the Beta chapter at the University College of Medicine in Richmond, Virginia, in 1900.

[5] Theta Kappa Psi later struggled; it would go on to merge with Phi Beta Pi in 1961, but this union was again dissolved in 1992.

[6] As of January 1, 2025[ref], Kappa Psi consists of 105 collegiate and 73 graduate chapters organized into 11 regional provinces.