To truly understand the history of the chapter you must go back to 1866, the year Westminster College first went in to debt. Rev. Robert Morrison, D.D., came to Missouri in 1876 as a pastor. On June 15, 1879 he was called by the Trustees to become the financial agent of the college. He accepted and moved to Fulton. Morrison never received a donation of over $150 but by the fall 1881 his work helped liquidate the College debt of more than $14,000. Robert Morrison was one of the orignal founders of the Phi Delta Theta International Fraternity and was largely responsible for establishing the Missouri Beta chapter of Phi Delta Theta in 1880. After his death "Father" Morrison was buried in the Fulton Cemetery.

Phi Delta Theta was the first Fraternity to have a chapter house at Westminster. This house was established in the Fall of 1901 and was the J. E. Watson house at the corner of Main and Ninth St. Several houses served briefly until 1915 when the Hamilton house was purchased and was used until 1926. The current chapter house was built in 1926-1927 and first used in the fall 1927.