Yost, at Michigan, blackballed Notre Dame after the Irish came to Michigan and beat him in 1909. Michigan, back then, was THE football team.
Notre Dame’s first win against Michigan came in 1909, a win that caused the
Detroit Free Press to write “Eleven
Fighting Irishmen wrecked the Yost machine this afternoon. The sons of Erin, individually and collectively representing the University of Notre Dame, not only beat the Michigan team, but dashed some of Michigan’s greatest hopes and shattered Michigan’s fairest dreams.”
Yost cancelled the next year’s game and then refused to schedule Notre Dame for the rest of his career at Michigan. Which meant that Notre Dame didn’t play Michigan again until after Yost retired in 1941.
Some believe that schools blackballing the Irish led to their nationwide schedule. The 1920s and 30s was a time when anti Catholicism was rife.
In 1926, Notre Dame, applied to join the Big Ten. Michigan and Yost were opposed to adding the Irish.
In 1999, the B1G itself now explored the idea with Notre Dame and Father Malloy released the following:
Why, then, not take the ultimate step in partnership and become a member of the Big Ten? That answer, in the end result, transcends the many individual factors, academic and athletic, that weigh either for or against conference affiliation. Ultimately, the answer lies in the institutional identity of Notre Dame, its overarching definition. Just as the Universities of Michigan or Wisconsin or Illinois have core identities as the flagship institutions of their states, so Notre Dame has a core identity, and at that core are these characteristics—Catholic, private, independent.