OK, I see what you're saying now. Or at least, I see what you meant to say. Your intention was to say that Semmes was not the greatest ships captain in American history, which is an opinion you can probably very easily defend.

But, what you said was:
"I don't believe American Captain is in that statement is it Nutty? Of course he wasn't even that either."

In that paragraph, the only thing that the word "that" in the second sentence could possibly refer to is "American Captain" in the first sentence. In order for "that" to refer to anything else, one has to go back two paragraphs before that, to find any reference to "great" captains. And you know good and well that your high school English teacher would never allow that. At least, mine wouldn't.

But I apologize for misunderstanding your intent. And while I do admire Semmes (he was a professor at LSU after the war, as well as a fine Naval officer), he would be up against some pretty serious competition were he to compete in a Greatest American Ship Captain contest.