Which university founded in 1818 is the oldest university west of the Mississippi River: Saint Louis University or Marquette University? 
Saint Louis University: Saint Louis University (SLU, ) is a private Roman Catholic four-year research university with campuses in St. Louis, Missouri, United States and Madrid, Spain. Marquette University: Marquette University is a private, coeducational Catholic university located in Milwaukee, Wisconsin, in the central United States.
i don't know