Delta Upsilon (ΔΥ), commonly known as DU, is a collegiate men's fraternity founded on November 4, 1834, at Williams College in Williamstown, Massachusetts.

Although historically found on the campuses of small New England private universities, Delta Upsilon currently has 76 chapters/colonies across the United States and Canada.

[8] Notable members include President of the United States James A. Garfield, president of Colombia Juan Manuel Santos, Canadian prime minister Lester B. Pearson, Linus Pauling, Joseph P. Kennedy, Lou Holtz, Kurt Vonnegut Jr., Charles Evans Hughes, Les Aspin, James Smith McDonnell and others.

Its founding came at the tail-end of the anti-Masonic hysteria that had recently swept the United States, though the idea that it was part of the popular backlash to Freemasonry has generally been rejected (a mysterious fire in 1841 destroyed the records of the first meeting of the Social Fraternity, erasing much of the organization's early history).

One particularly violent incident occurred in 1839 when Oudens assaulted the Kappa Alpha house, driving its occupants to the top of Consumption Hill.

saw the organization formally change its name to Delta Upsilon, standardize insignia and ritual throughout all its member chapters, and establish a centralized administrative structure.

[9] According to Delta Upsilon, the reason for this change was because it had been absolutely victorious in its battle against secrecy, "the character of the secret societies so altered, that hostility toward them decreased".

[17] This explanation has been more skeptically received by some, with one period observer caustically noting that Delta Upsilon "reveals very little more of what it does than the latter [secret fraternities]".

[20] Writing in 2013, Benjamin Wurgraft of the New School for Social Research commented that Delta Upsilon's changes made it "nothing more than another fraternity—a rival for pledges rather than a force for unity".

[14] In 1898, Delta Upsilon joined the recent trend of fraternity expansion into Canada by chartering a chapter at McGill University in Montreal.

Gen. John Arthur Clark, the celebrated former commander of the Seaforth Highlanders and a Member of Parliament from Vancouver, was elevated to "international president", the fraternity's penultimate office, in 1944, holding it for three consecutive terms.

That year's sitting of the Undergraduate Convention was dissolved by emergency action of DU leadership to "prevent open dissension" in the wake of the election of an African-American as president of the Brown University chapter.

The initiation was significant as it was the first time in more than a century that Delta Upsilon established a chapter at a school where no previous fraternities and sororities existed.

A Delta Psi historian later claimed the withdrawal was due to the expenses the fraternity was incurring sending delegates to the meetings of the Anti-Secret Confederation.

A further shot across the bow of the international fraternity came when Harvard requested headquarters stop sending copies of the Delta Upsilon Quarterly because they "littered up the house".

Harvard responded by declaring it didn't recognize the authority of DU headquarters as Delta Upsilon had ceased to exist in 1909.

Schwarz Jr.[40] Following the courtroom triumph of the DU headquarters, it expelled the rebellious members and initiated a hand-picked pledge class to continue the chapter.

Terry Bullock, then Delta Upsilon international president, wrote of the return of Brown that "there is no greater joy than the reconciliation of a family estranged for many years".

[45][46] In 1996 Kappa Delta Upsilon was banned from campus for 5 years due to the circumstances surrounding a fire in its basement.

In the new revision, the old Preamble was completely stricken and the following text was added to Article 1, Section 2: "The objects of this Fraternity shall include the promotion of friendship, the exertion of moral influence, the diffusion of liberal culture, and the advancement of equity in college affairs.

[14] The "Four Founding Principles" are currently: the Advancement of Justice, the Promotion of Friendship, the Development of Character, and the Diffusion of Liberal Culture.

The hat band was initially only sold through the head office, however, in 1922 Delta Upsilon began licensing a small number of hatter shops, primarily in Manhattan and New England, to produce and sell the puggaree for $1 if the customer first displayed their badge to the clerk as a mark of identification.

Reared in adversity, so shalt thou never Let from thy alters die the life-giving flame; Hands gripped in loving clasp, all brothers forever,

The building was financed with a bequest from Lester E. Cox, a University of Pennsylvania chapter alumnus who left half his estate to the fraternity.

According to the fraternity, the reproduction of early covers of the magazine was authorized by Time editor-in-chief Hedley Donovan, a member of Delta Upsilon's University of Minnesota chapter.

[58] In 1906 the Alpha Tau Omega Palm declared it was, among all fraternity journals, second in quality only to the Kappa Sigma Caduceus.

[17] The fraternity's membership roster includes United States President James A. Garfield (Williams 1856), Chief Justice of the United States Supreme Court Charles Evans Hughes (Colgate and Brown 1881), United States Senator-Vermont Justin S. Morrill (Middlebury 1860), former Commander in Chief of the US Central Command Tommy Franks (Texas 1963), author Stephen Crane (Lafayette and Syracuse 1894), author Kurt Vonnegut Jr. (Cornell 1944), former chairman and CEO of Walt Disney Co. Michael D. Eisner (Denison 1964), and Nobel Prize recipients Charles Dawes (Marietta 1884), Christian B. Anfinsen (Swarthmore 1937), and Edward C. Prescott (Swarthmore 1962).

[60] Two Delta Upsilon fraternity members, Alfred P. Sloan (Technology 1895) and Charles F. Kettering (Ohio State 1904), joined together in 1945 to found the Sloan-Kettering Institute, which is now part of the world's oldest and largest private cancer research facility, the Memorial Sloan-Kettering Cancer Center.

In 2018, the chapter of Delta Upsilon at the University of Washington in Seattle had its charter revoked for beating pledges and forcing them into servitude of senior undergraduate members.

[61] In April 2019, a document was anonymously leaked containing unofficial "minutes" written by members of the Swarthmore College local Phi Psi fraternity between 2013 and 2016.