Factual error: The Big Game in Rudy takes place in 1975, which means Rudy started at Holy Cross in 1972. To get to Holy Cross, he takes a bus there. In that touching goodbye scene with his father at the bus station, look at the mural in the back ground. It is a depiction of the New York skyline with the Twin Towers, which were not completed until 1973, after that scene should have taken place.
Factual error: When Rudy first arrives on Notre Dame's campus, he is advised to attend Holy Cross junior college to get his grades up so he can be eligible to attend Notre Dame. According to historical data, Rudy enrolled at Holy Cross in 1972. But in the scene when Rudy first walks onto Notre Dame's football field from the end zone, the Goal Post is at the end of the end zone. NCAA goal posts were not moved to the back of the end zone until 1974, so the goal post should have still been on the goal line in 1972.
Factual error: When Rudy is reading his acceptance letter from Notre Dame, he quotes that he was accepted as a freshman. Earlier in the film, he said to Father Cavanaugh that this was his last chance, because Notre Dame doesn't accept senior transfers. The acceptance letter should have listed him as a junior transfer student.