An interesting tidbit about the assassination:

After the failure of the Bay of Pigs operation, JFK put his brother Bobby in charge of working with the CIA to get rid of Castro. The CIA turned to the mob. They had a grudge against Castro because before he took over, the Mafia ran the gambling business in Cuba.
It's ironic to note that while we never succeeded in Killing Castro, both the Kennedy brothers died at the hands of assassins.