Phi Delta Theta

Phi Delta Theta (ΦΔΘ), commonly known as Phi Delt, is an international secret and social fraternity founded at Miami University in 1848 and headquartered in Oxford, Ohio. Phi Delta Theta, along with Beta Theta Pi and Sigma Chi form the Miami Triad. The fraternity has over 190 active chapters and colonies in over 43 U.S. states and five Canadian provinces and has initiated more than 277,000 men between 1848 and 2021. There are over 160,000 living alumni. Phi Delta Theta chartered house corporations own more than 135 houses valued at over $141 million as of summer 2015. There are nearly 100 recognized alumni clubs across the U.S. and Canada.

The fraternity was founded by six undergraduate students: Robert Morrison, John McMillan Wilson, Robert Thompson Drake, John Wolfe Lindley, Andrew Watts Rogers, and Ardivan Walker Rodgers, who are collectively known as The Immortal Six. Phi Delta Theta was created under three principal objectives: "the cultivation of friendship among its members, the acquirement individually of a high degree of mental culture, and the attainment personally of a high standard of morality". These cardinal principles are contained in The Bond of Phi Delta Theta, the document to which each member pledges on his initiation into the fraternity.

Among the best-known members of the fraternity are Benjamin Harrison, the 23rd President of the United States, Vice President Adlai Stevenson I, Baseball Hall of Fame member Lou Gehrig, actor Burt Reynolds, architect Frank Lloyd Wright, astronaut Neil Armstrong, and John S. McCain Sr., U.S. Navy Admiral and grandfather of John McCain.