While Alexander Hamilton and Aaron Burr’s 1804 duel is notorious in history and pop culture, a lesser-known deadly duel occurred three years earlier between Hamilton’s oldest son, Philip, and George Eacker, a critic of Hamilton and supporter of Burr.

Hamilton took great pride in his son’s academic achievements. He wrote to him regularly while Philip was studying at boarding school, and created a rigorous set of rules to govern Philip’s study schedule. In 1797, when Philip was a young teenager, he contracted a deadly illness and Hamilton reportedly “administered every dose of medicine” to his son during his recovery.

The close relationship between father and son may have contributed to Philip’s eagerness to defend his father’s name. Eacker, a 27-year-old lawyer, had made a speech in July accusing Alexander Hamilton of being willing to overthrow Thomas Jefferson’s presidency by force. In the speech, Eacker accused Hamilton of misusing his position as Inspector General during the Adams administration to intimidate his political enemies. On November 20, 19-year-old Philip and his friend Richard Price confronted Eacker about the speech when the three men were at a social event. After Eacker insulted them, the boys challenged Eacker to a duel. Dueling was already illegal in New York, so the men planned to meet in New Jersey. Eacker and Richard Price took the field first at Weehawken, on November 22. They exchanged shots, but no one was injured; according to convention, honor was satisfied. The next day, Philip faced Eacker and fell to a ball from Eacker’s smoothbore dueling pistol. He died the next day. The death caused a massive strain on the Hamilton family and led to the nervous breakdown of Hamilton’s daughter Angelica.

Robert Troup observed about Hamilton after Philip’s death in a December 5, 1801 letter to Rufus King:

Never did I see a man so completely overwhelmed with grief as Hamilton had been. The scene I was present at, when Mrs. Hamilton came to see her son on his deathbed (he died about a mile out of the city) and when she met her husband and son in one room, beggars all description! Young Hamilton was very promising in genius and acquirements, and Hamilton formed high expectations of his future greatness!”

Alexander Hamilton was killed three years later, on the same dueling grounds in Weehawken and with the same dueling pistols.