In the fall of 1906, sixteen university friends expressed their aspiration to continue their amity further than college, and into the rest of their lives. It was then that these civil engineering juniors decided to commence the organization that came to be Triangle Fraternity at the University of Illinois. Soon thereafter, Triangle was incorporated on April 15, 1907 in the state of Illinois. These Founders established the principles of friendship, courage, brotherhood, high ideals, honor, and character in their association.

However, our founders extended their fervor beyond their state, and on April 8, 1909 our second chapter was launched at Purdue University, making Triangle a national fraternity. At first, Triangle bounded its membership solely to civil engineering students. After World War I, Triangle broadened its association to every sort of engineering as well as architecture. By the early 1960s, Triangle approved accepted majors of mathematics, physics, and chemistry and the addition of computer science in 1983. Triangle’s strong growth in the early decades of the 1900s can be attributed to the fact that the first three chapters (Illinois, Purdue, and Ohio State) ranked amid the top 10 of engineering schools in enrollment. In addition, the force of the large demand of civil engineering due to the expansion of railroads and their construction and operation further helped.

Throughout the 1990s, Triangle National began to institute stronger ties with chapters with the use of the internet and email as better communication tools. The World Wide Web also provided a manner by which to tender services and resources to Triangle members. As a public charity, Triangle Education Foundation presented a means for tax-deductible donations to facilitate support to Triangle. This allowed scholarship sponsorships for academic assistance and leadership training.