April 21st, 753 B.C. is the traditional date observed for the founding of Rome.

On April 20th, 1972, Apollo 17 landed on the moon.

On April 19th, 1775, the "shot heard 'round the world" was fired, beginning the Revolutionary War.

On April 18th, 1775, the famous midnight ride of Paul Revere took place.

On April 17th, 1521, Martin Luther spoke before the Diet of Worms, refusing to recant his teachings.

On April 16th, 1912, Harriet Quimby became the first woman to fly a plane across the English Channel.

On April 15th, 1865, Andrew Johnson became the 17th President of the United States.

On April 14th, 1865, Abraham Lincoln was shot by John Wilkes Booth.

On April 13th, 1861, Fort Sumter surrendered in the American Civil War.

On April 12th, 1945, President Franklin D. Roosevelt died, and Harry Truman was inaugurated as President of the United States.

On April 11th, 1970, Apollo 13 was launched.

On April 10th, 1912, the RMS Titanic begin its ill-fated voyage.

On April 9th, 1967, the first Boeing 737 took its maiden flight.

On April 8th, 1742, Handel's "Messiah" was performed for the first time, in Dublin.

On April 7th, 1805, Beethoven's Third Symphony was performed publicly for the first time.

On April 6th, 648 BC, the ancient Greeks made the first documentation of a solar eclipse.

On April 5th, 1621, the Mayflower set sail from Plymouth to return to Great Britain.

On April 4th, 1581, Francis Drake completed his circumnavigation of the world and was knighted by Elizabeth I.

On April 3rd, 1860, the first Pony Express run was begun.

On April 2nd, 1513, Ponce de Leon became the first known European to set foot on Florida.