Ball State's board selected Geoffrey Mearns for the position last month, but wasn't certain when he would start.
An email Ferguson wrote to university officials in March 2015 claims the board chairman micromanaged him on many issues.
The NCAA is now facing 43 class-action lawsuits related to the handling of concussions by Division I football programs after 18 more were filed this week.
The group from Ball State when on what's called a "person to person tour," one of several categories of travel Americans are permitted to take.
The founder of the pizza chain is a 1983 Ball State graduate.
Paul Ferguson has served as the university's president since 2014.
Letterman will be remembered in Muncie for the start he got on WBST radio, now home of Indiana Public Radio, while a student in the late 1960s.
The findings show that a higher use of TIFs reduces employment and the number of business establishments in a county.
Paul Ferguson, the current president at the University of Maine, will be Ball State University's 15th president.
Ball State University banned a class that taught intelligent design, and now Indiana lawmakers are questioning that decision.