[6] The official story told by Cole and Albert Cross is that on November 2, 1909, Cole, Percival C. Morse, and Clyde K. Nichols reorganized the Cosmopolitan Law Club, a society of Boston University law students into the Loyal Collegiate Associates, which was renamed Lambda Chi Alpha in 1912.

Instead, according to the alternative account, Cole shared an apartment with James C. McDonald and Charles W. Proctor, who later joined Sigma Alpha Epsilon.

He corresponded with or visited 117 institutions by 1912, when a group at Massachusetts Agricultural College accepted a charter to become Gamma Zeta.

[9] In the years that followed, a divide opened between Cole and a group of young alumni led by Mason, Ernst J.C. Fischer of Lambda Chi's Cornell University chapter in Ithaca, New York, and Samuel Dyer of the University of Maine chapter in Orono, Maine.

With the help of the North American Interfraternity Conference in identifying local groups, and Theta Kappa Nu's policy of granting charters quickly to organizations with good academic standards, the fraternity grew quickly and had approximately 2,500 initiates in 40 chapters by the end of 1926.

[11] During the Great Depression, both Theta Kappa Nu and Lambda Chi Alpha saw membership decrease and chapters shut down.

[12] The merger ceremony was held at Howard College (now Samford University) chapter of Theta Kappa Nu in Birmingham, Alabama.

[15] At schools where chapters of both fraternities previously existed, the two merged and retained Lambda Chi's Zeta recognition.

[26] In 2017, Lambda Chi Alpha announced a trial partnership with the St. Baldrick's Foundation, a Monrovia, California-based organization that funds childhood cancer research.

[27] In 2019, Lambda Chi Alpha announced a partnership with The Jed Foundation, a Boston-based non-profit organization that seeks to protect emotional health and prevent suicide for teens and young adults.

Together, they are launching Lambda Chi Alpha Lifeline, an online mental health resource center tailored from the foundation's ULifeline website, which provides college students with information about emotional health issues and specific resources available to them on their respective campuses.

Movember has recently become a primary philanthropic focus for Lambda Chi Alpha and the fraternity's national administrative office.

As a result, the first 22 chapters were designated Α, Γ, Ε, Ζ, Ι, Λ, Β, Σ, Φ, Δ, Π, Ο, Μ, Τ, Η, Θ, Υ, Ξ, Χ, Ω, Κ, Ν, Ρ, Ψ.

In 1945, Harry S. Truman, the 33rd president of the United States, was made an honorary initiate of the Lambda Chi Alpha chapter at the University of Missouri.

[31][32] Lambda Chi Alpha is referenced in the 2005 Kenny Chesney song "Keg in the Closet", which includes the lyrics: "This ol' guitar taught me how to score, right there on that Lambda Chi porch, Mary Ann taught me a little more, about wanting what you can't have.

In 2023, the University of New Orleans chapter was featured in Season Seven, Episode 1 of the Netflix series, Queer Eye.

[34] In October 1958, a Lambda Chi pledge at MIT, Oliver R. Smoot, gained global recognition when his MIT fraternity brothers had him lay down repeatedly on Harvard Bridge between Boston and Cambridge while they measured the bridge using his height, which turned out to be 5 feet 7 inches.

[36][37] In October 1958, the fraternity expelled its Hamilton College chapter in Clinton, New York, for insisting on a non-discrimination policy for admitting members.

In May 1988, James Callahan, an associate at Rutgers University in New Brunswick, New Jersey, died of an alcohol overdose from a Lambda Chi Alpha drinking hazing ritual.

[41][42] In May 2014, following a yearlong investigation, seven members at the University of Illinois Urbana-Champaign were arrested and charged with using and distributing illegal drugs.

The cooler was discovered along with a half-mile wide swath of trash left behind at Shasta Lake in Northern California, where an estimated 1,000 students had docked houseboats over the weekend.

[47] In January 2017, the Indiana University-Bloomington chapter in Bloomington, Indiana, was placed under a two-year suspension after an associate member reported hazing activities occurring in the chapter house to the university, which allegedly included brutal physical exercise, liquor hazing, and the act of capping were mentioned in the report.

In April 2018, the chapter at Cal Poly SLO in San Luis Obispo, California[48] was placed on interim suspension after social media images surfaced depicting members dressed up as gang members with one wearing blackface during the school's multicultural celebration weekend.

[49] In August 2018, the chapter at Butler University in Indianapolis was suspended by the school, which did not cite a specific reason for the suspension.