May 12, 1949 – Soviet Russia lifts its blockade of Berlin that began June 24, 1948. American and British flyers had successfully executed an airlift that delivered 2.3 million tons of food and supplies during 278,000 flights to the isolated West Berlin citizens.
May 14, 1796 – The first documented medical test of the smallpox vaccine was initiated by Dr. Edward Jenner, a rural English physician.
May 17, 1875 – The first Kentucky Derby horse race is run at Churchill Downs in Louisville. It is the oldest continuously held major sporting event in the U.S.
May 17, 1954 – In Brown v. Board of Education, the U. S. Supreme Court unanimously rules the segregation of public schools “solely on the basis of race” denies Black children equal education opportunity. The case against segregation was argued by future Supreme Court Justice Thurgood Marshall.