Back in Britain, the Fab Four did please
But could their sound survive overseas?
The moptops gave a go
On the Sullivan Show
Beatlemania spread like a disease

Event: The Beatles appear on the Ed Sullivan Show for the first time
Year: 1964
Learn more: http://en.wikipedia.org/wiki/The_Beatles

Now, because this is a special occasion, I present an additional bonus limerick:

Listen up, ’cause I’m telling you, dude
This date is much with hist’ry imbued
Not by treaties, or wars
Or amazing sports scores
On this day, a new website debuted

Event: The Wandering Wordsman launches
Year: 2009
Learn more: Just stick around. You don’t have to go anywhere else for this one.