The election of Thomas Jefferson, and the admittance of new states into the Union, led to a significant decline in the power of both the Federalists and their leader, Alexander Hamilton. Some of the more radical Federalists demanded that a new union of New England States be created. They came to Hamilton, who refused to even consider such a suggestion.
After Hamilton turned the Federalist radicals away, they approached Aaron Burr. Burr was Vice President and a contender for the governorship of New York. The radical Federalists offered Burr their support in the gubernatorial race, in return for his support of their new union. Burr agreed; but, despite Federalist help, he was defeated in the New York election for governor. He blamed his defeat on Alexander Hamilton. It was Hamilton who, with the election deadlocked in 1800, had preferred Jefferson as President over Burr.
After 35 deadlocked ballots, Hamilton threw his support to Jefferson. As a result, Burr demanded that his honor be satisfied and that Hamilton agree to a duel.
Hamilton opposed duels in principle, having lost his son to a duel two year before. Despite this fact, Hamilton feared being labeled a coward, and thus felt compelled to participate.
Early in the morning, Hamilton left his New York home, without alerting his family. At 6 a.m., he was ferried across the Hudson River to a grove beneath the Palisades. The agreed distance was ten paces. Burr turned, carefully aimed and fired at Hamilton. Hamilton was left mortally wounded.