60% of Americans did not go to college.

[BattleofHodow]

But that is not the reason Harvard might have a low percentage of southern students

Few 18 year olds want to go to college two thousand miles away from home. In the south, they are more likely to aspire to attend an elite southern private university, Rice, Emory, Duke, et al.

I know hundreds of people from California and Oregon who went to college or grad school, and I can count on two hands the number who moved more than 500 miles to attend school. I suspect the percentage of California students at Yale is pretty bloody low.

Most of our best & brightest aren't Southerners.
Maybe Charles H. Townes from South Carolina.

A few appear to be descended from earlier arrivals & colonial like Thomas Edison, Robert H. Goddard, Linus Pauling, Benjamin Franklin, John Frank Enders, Maybe William Shockley, John Garden, Dennis Ritchie,Warren Weaver, Hugh Dryden, William Standish Knowles, Robert Milliken,F Albert Cotton, Alan Curtis Kay,Norman Foster Ramsey, Edward Mills Purcell.

A lot of them have been from more recent arrivals Einstein a Jewish immigrant from Germany, Nikola Tesla a Serbian immigrant, Abraham. Michelson a half Polish half Jewish immigrant, Italian immigrant Henrico Fermi, Jewish Marvin Minsky, Polish American Steven Wozniak Norweigan Ernest Lawrence, Polish immigrant Nikodem Poplawski, Jewish origins Richard Feynmann from Poland & Russia, Leo Szilard a Jewish immigrant from Hungary, Edward Teller a Jewish immigrant from Hungary, Frank Wilczek a Polish - Italian, Hans Bethe a half German half Jewish immigrant from Germany, Igor Sikorsky a Polish Ukrainian from Russia, John Von Neumann a Jew from Hungary, Stanislaw Ulam Jew from Poland, Wojchiech Zurek a Polish immigrant. Eugene Wigner a Jew from Hungary, Wolfgang Pauli from a Czech Jewish origin immigrant from Austria, Alexander Graham Bell a Scottish immigrant, George Garnow a Russian immigrant, Michio Kaku a Japanese American, John McCarthy half Irish & half Lithuanian Jewish, Paul Batman a Jewish immigrant from Poland, Jack Szostak a Polish roots immigrant from Britain, Karl Jansky of Czech origins,Maria Siemenow a Polish immigrant, Frank Piasecki a Polish American, Paul Berg a Jew, George Fantasy Jewish,Donald A Glaser k from Russian Jews, Richard Lenski a Prussian German Polish origin, Stanley Norman Cohen Jewish,Arthur Ashkin Ukrainian Jewish Ronald Hoffman from Polish Jews,, Warner Von Braun a German from Polish territory, Robert Oppenheimer a Jew from Germany, Polish immigrant Alexander Wolczscan, Ukrainian American Alex Fillipenko etc.

I could keep going on & on.