Speaking of historic dates in April, did you know that April the 15th is very important as well?
The sinking of the Titantic, in 1912, which hit the iceberg on the 14th but succumbed on the 15th:
The death of Abraham Lincoln in 1865--similarly, he was shot on the 14th but succumbed on the 15th:
On the plus side, it's also the birthday of Leonardo da Vinci (1452), Emma Watson (1990) and myself! (1980)