Fidel Castro's Mass Murder by the Numbers
Fidel Castro shed blood on a scale unimaginable in American terms. His butchers executed perhaps 15,000 prisoners, according to academic estimates cited by Wikipedia:
British historian Hugh Thomas, in his study Cuba or the pursuit of freedom stated that "perhaps" 5,000 executions had taken place by 1970, while The World Handbook of Political and Social Indicators ascertained that there had been 2,113 political executions between the years of 1958–67.
That was in a country of 7 million. In per capita terms, that's the equivalent of about 680,000 executions in the United States of America with our population of 318 million. What's 680,000? The entire population of Denver or Seattle. Imagine taking every man, woman, and child of a major American city and murdering them. That's the scale of Fidel Castro's crimes.
680,000 is a bit less than the standard estimate for total military deaths in the American Civil War. Imagine standing 680,000 soldiers against a wall -- all the dead of Antietam, Gettysburg, Cold Harbor Chickamauga and every other battle of the Civil War -- and shooting them dead in cold blood. That's the equivalent of Fidel Castro's mass murder.
Stalin, Hitler, Mao and Pol Pot killed more people in relative terms. After that, it's hard to find a tyrant with a bigger body count than Fidel. To speak of him with anything but a curse is an insult to the memory of his victims.