May 1913

Tuesday 13:

Igor Sikorsky becomes the first man to pilot a four-engine aircraft.

Wednesday 14:

New York Governor William Sulzer approves the charter for the Rockefeller Foundation, which begins operations with a $100 million donation from John D. Rockefeller.

Thursday 29:

Igor Stravinsky's ballet score The Rite of Spring is premiered in Paris.

Friday 30:

First Balkan War: A peace treaty is signed in London ending the war. Albania becomes an independent nation.

Saturday 31:

The Seventeenth Amendment to the United States Constitution, authorizing direct election of United States Senators, is declared ratified.