Here’s a look at some interesting events that took place on this day in history:

1860 – The first successful United States Pony Express run begins (More info)

1882 – Jesse James is killed by Robert Ford, one of his own gang members (More info)

1948 – President Harry S. Truman signs the Marshall Plan, authorizing $5 billion in aid for 16 countries (More info)

1955 – The ACLU announces it will defend Allen Ginsberg’s book ‘Howl’ against obscenity charges (More info)

1968 – Martin Luther King, Jr. delivers his ‘I’ve Been to the Mountaintop’ speech (More info)