Alexander Hamilton, the subject of last year’s runaway Broadway hit, has come alive for audiences nationwide, but what about the man who killed him in that infamous 1804 duel? That man was Aaron Burr, the Vice President of the United States at the time. Killing Hamilton ruined his political career, but he lived for three more decades, casting a long spell over American history. As historian Gordon S. Wood said, “Burr is no ordinary historical figure. His life is scarcely credible.”

The animosity between Hamilton and Burr dates at least to the deadlocked election of 1800, in which both Thomas Jefferson and Burr received the same number of electoral votes for President (even though Burr was the Vice Presidential candidate). The deadlock was resolved by the House of Representatives, which chose Jefferson after 36 ballots.

Alexander Hamilton, a Federalist, opposed Jefferson and Burr, both of whom were Democratic-Republicans. But he feared Burr more, and worked to get Federalists in Congress to vote for Jefferson. In this fascinating letter to Harrison Gray Otis, Hamilton explains why.

Hamilton thought Burr (whose debts were legendary) would inevitably be corrupt because he lacked private wealth. Though Hamilton himself rose up from obscurity, he believed in a ruling elite with wealth and manners. Burr had a notable American lineage—his father was president of the College of New Jersey (Princeton) and his grandfather was the theologian Jonathan Edwards—but no money. He was an aristocrat but also probably far more democratic and far more of a politician as we now understand the term. Burr made no bones about using his office—whether it was his law firm, U.S. Senate, New York legislature, or Vice Presidency—for selfish purposes. He was not, at least, a hypocrite.

Indeed, Wood argued that Burr was “a traitor not to his country but to his class.” Burr was self-serving, routinely scheming to avoid bankruptcy. This was not how the founding fathers, who were supposed to be enlightened, nonpartisan, and disinterested landed gentry, were supposed to govern. Even Thomas Jefferson loathed Burr, as he tried to bend the Constitution in an attempt to convict his erstwhile VP of treason in 1807.

One of Hamilton’s most damning charges against Burr was that he “never appeared solicitous for fame.” Every other founder, including Hamilton, made a real effort to be remembered by their letters and papers. Nonetheless, as Wood noted, it was Burr who became “the most romanticized and vilified historical character in American literature.”