Just over 40 years ago, only around 1 in 10 US adults had a four-year college education. Today, that rate has nearly tripled. This gif shows the geography of that explosion.
College degrees clearly became more commonplace nationwide over the last 40 years, but the geography of them is striking today. Broadly speaking, the South remains the place where degrees are the least common. Meanwhile, cities — and particularly the northeastern Amtrak corridor — are where college graduates have concentrated.