"Ghosts from the Past"

This is a simple question:

What are John Wilkes Booth and Lee Harvey Oswald famous for?

Ok since all of you people who answered are getting too cocky, I want you to tell me what each of their occupations are and what was the exact event that triggered of their rage so as to carry out what ever they did......

And don't copy paste from the first search results from google cause i've researched a little on these people and there is more to them than you just guessed