Final answer:
Phi Delta Theta was founded in the Elliot Hall of Music at Miami University in Ohio. The fraternity was established on December 26, 1848, by six undergraduate students in a second-floor room of what was then Old North Hall.
Step-by-step explanation:
The founder's room where Phi Delta Theta (Phi Delt) was founded is known as the Elliot Hall of Music located at Miami University in Oxford, Ohio. On December 26, 1848, six undergraduate students came together in a second-floor room of Old North Hall (now called Elliott Hall), coming up with the idea for a new fraternity. The six founders of Phi Delt were Robert Morrison, Robert Thompson Drake, John Wolfe Lindley, Ardivan Walker Rodgers, Andrew Watts Rogers, and Philip Springer Burnham. It was in this room that they established the three cardinal principles: Friendship, Sound Learning, and Moral Rectitude.