The overwhelming majority of people in the country still attend relatively local schools. The median distance students with a higher range ACT (28-36) score travelled for college [was 113 miles, and that was far higher than most other students](http://www.act.org/newsroom/how-far-from-home-do-us-students-travel-to-attend-college/). When one considers that 113 miles usually means that a student will stay in state for much of the US, it’s hardly surprising that local students elevate near local schools.
By the way, I suspect people on both coasts traveled about the same distance for college as students in the middle of the country. In fact, there is some data which shows that those in the Northeast are among the [least geographically](https://www.census.gov/hhes/migration/data/acs/state-to-state.html) mobile people in the entire country. When migration to nearby, but technically out of region, states is considered, the data suggests the people become even less migratorily mobile.