[1] In 1906, these schools formed a sports compact that formalized a three-way football competition which began in 1878, predating the Ivy League.

In this respect Harvard, Yale, and Princeton are the Western Counterparts of Oxford and Cambridge, and are maintained largely for the sons of rich men.

The pattern of upper-class male college preference, as deduced from a counting of noses in the various Social Registers, can be summed up as "The Big Three and a Local Favorite.

"[6]Burt continued, "Every city sends or has sent its Socially Registered sons to Harvard, Yale, and Princeton, in some preferred order, and to one local institution.

The connection between certain colleges and social ranking is old; Jerome Karabel, in a note citing Kenneth Davis, says that "in the mid-eighteenth century, the [president of Harvard] personally listed students when they enrolled, according to ... 'to the Dignity of the Familie whereto the student severally belong'—a list that was printed in the college catalogue and that determined precedence in such matters as table seating, position in academic processionals, even recitations in class.

"[7] Ronald Story, however, says that it was during “the four decades from 1815 to 1855” that “parents, in Henry Adams′ words, began sending their children to Harvard College for the sake of its social advantages.”[8] A further intensification of the importance of the Big Three occurred during the 1920s; According to E. Digby Baltzell,[9] “in a … managerial society, the proper college degree became the main criterion for potential elite status… it was during the [1920s] that certain institutions of high prestige, such as Harvard, Yale, and Princeton (and Stanford on the West Coast) became all-important as upper-class-ascribing institutions.” Not coincidentally, this was also the era when the Big Three became concerned by “the Jewish problem” and began instituting interviews, essays, and judgements of “character” into the admissions process.

The athletic agreements among the three universities were first formalized in 1906, although their football teams had been engaging in three-way competitions, which newspapers had been referring to as "HPY," since 1878.

The Big Three made further formal agreements in 1916 and 1923, and although in part they have now been superseded by the Ivy League, formed for football in 1945 and for other sports in 1954, the three universities still sponsor events that involve only themselves.

This led to a hiatus in games between Harvard and Princeton which caused Big Three competition to be suspended for eight years, although Yale continued to play both opponents during that period.

Student attrition due to the Civil War and a scandal over college finances led to a decline at Union that caused it to lose ground and drop from the group.