The book <em>American Brutus</em> talks about John Wilkes Booth, who was responsible for the assassination of Lincoln. This is a reference to the assassination of Julius Caesar by Brutus. However, the character also resembles Cassius in several ways:
Cassius was politically savvy, and when he developed his plan to kill Julius Caesar, he was worried about the abuses of Julius Caesar. Similarly, John Wilkes Booth was worried about the political consequences of Lincoln.
Cassius is the real mastermind of the assassination and ringleader of the conspirators. Similarly, Wilkes Booth was the mastermind behind he assassination of Lincoln.
Wilkes Booth believed that Lincoln could be compared to Caesar, and that they were both disregarding the law for their own gain. This kind of thinking is similar to the way Cassius thought in the play.