1792

The Buttonwood Agreement, a document codifying rules for securities trading, was signed by 24 New York stockbrokers, marking the formation of the New York Stock Exchange.

1875

The first Kentucky Derby was held; the race was won by Aristides, ridden by jockey Oliver Lewis.

1946

President Harry S. Truman seized control of the nation’s railroads, delaying — but not preventing — a threatened strike by engineers and trainmen.

1954

A unanimous U.S. Supreme Court handed down its Brown v. Board of Education of Topeka decision, which held that racially segregated public schools were inherently unequal and therefore unconstitutional.