Dueling in the United States was never outlawed by one single nationwide law on a single date; instead, it was banned piece by piece by Congress, states, and the military over time.

Quick Scoop

  • In 1839, Congress passed a law banning dueling in Washington, D.C., after a congressman was killed in a duel nearby.
  • By 1859, at least 18 states had already outlawed dueling by statute, though it continued informally in parts of the South and West.
  • The U.S. military banned dueling under early Articles of War (from 1775 and 1806), and modern military law (UCMJ Article 114) still explicitly prohibits it.
  • By the early 20th century, dueling had effectively disappeared in practice as state laws were enforced and public opinion turned against it.

So if you’re asking “when was dueling outlawed in the US,” the closest simple answer is:

By the late 19th to early 20th century, dueling was illegal almost everywhere in the U.S., with a key milestone being the 1839 federal law banning duels in Washington, D.C., and a majority of states banning it by 1859.

A few colorful details

  • Washington, D.C. banned dueling in 1839 after the 1838 duel in which Rep. William Graves killed Rep. Jonathan Cilley at the Bladensburg dueling grounds just over the D.C.–Maryland line.
  • Many state constitutions (like West Virginia’s) still contain explicit anti‑dueling language, a leftover from the era when politicians had to swear they had never fought a duel.
  • Even when statutes existed, 19th‑century juries often refused to convict duelists, which is why the practice lingered socially long after it was technically illegal.

Small timeline snapshot (HTML table)

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Year / Period What happened
1775 & 1806 U.S. Articles of War for the military include bans on dueling.
1838 Famous Cilley–Graves duel near Washington, D.C., sparks outrage.
1839 Congress bans dueling in Washington, D.C. by law.
By 1859 18 states have laws outlawing dueling.
Late 1800s–early 1900s Dueling becomes rare and then vanishes as laws are enforced and public opinion turns.

Information gathered from public forums or data available on the internet and portrayed here.