Miami University (Ohio) was the birthplace of...
Beta Theta Pi (1839)
Phi Delta Theta (1848)
Sigma Chi (1855)
FYI. Miami was also the birthplace of Delta Zeta (1902) and Phi Kappa Tau (1906).
THE “MIAMI TIRAD”
In 1833, one year after its founding at Hamilton College, Alpha Delta Phi established its second chapter at Miami University, Oxford, OH. Displease with Alpha Delta Phi’s control of campus leadership at Miami, another group of students banded together in 1839 to establish Beta Theta Pi, the first fraternity to be founded west of the Alleghenies.
Phi Delta Theta, founded at Miami, owes its origins to a student prank, the famous “snow rebellion,” which started as a frolic and ended in open defiance of the college authorities. The students packed enormous quantities of snow in the entrances to the college buildings, thus preventing the faculty from entering the classrooms for two days. Expulsion of more than twenty students followed, including all the Alpha Delta Phi but one and all of the Beta Theta Pis but two. Thus both fraternities became inactive at Miami and remained so until 1852. Meantime, Phi Delta Theta was organized in December 1848, and gained a foothold before her rivals could reestablish themselves.
Miami University is likewise the birthplace of a third general fraternity, Sigma Chi. Six men who have been members of Delta Kappa Epsilon, which has entered Miami in 1852, founded it in 1855, after it’s founding at Yale in 1844. These six students had disagreed with their chapter over the election of a representative in a college oratorical contest and walked out to start a fraternity of their own.
Thus Beat Theta Pi, Phi Delta Theta, and Sigma Chi form the “Miami Triad.”
http://www.fiji.org/history.htm#THE%20“MIAMI