When the U.S. Constitution was negotiated, state representation in Congress included counting the slave population as 60% and so gave the South representation far beyond the norm. This imbalance, it turns out, was instrumental in giving Thomas Jefferson the Presidency in 1800 and so changed the course of American history irrevocably.
Jefferson, although he had many good qualities, comes off in this history as not having the highest morals. His bitter enemy, Arnold Pickney, although portrayed poorly in other histories, gets a better treatment in this one. But the hero of the book is John Quincy Adams, who, having lost the Presidency after one term, returned to Congress as a Representative and fought the good fight against the monstrous institution of slavery to the end of his life. As one involved in the Civil Rights movement of the 60s, my appreciation for this gallant warrior was enhanced by this book.