August 9 – The Arikara War breaks out between the Arikara nation and the United States, the first American military conflict with the Plains Indians.
August 23 – Hugh Glass is attacked and mauled by a sow grizzly bear and left for dead in the Missouri Territory. He crawls 200 miles before reaching help, events depicted in The Revenant (2015 film).
September 22 – Joseph Smith first goes to the place near Manchester, New York, where the golden plates are stored, having been directed there by God through an angel (according to what he writes in 1838).
November 15 – Lone Horn succeeds (probably) his father, and becomes chief of the MinneconjouSioux; he will be chief until his death on October 16, 1875.
December 2 – Monroe Doctrine: US President James Monroe delivers a speech to the U.S. Congress, announcing a new policy of forbidding European interference in the Americas and establishing American neutrality in future European conflicts.
Middlebury College, Vermont, becomes the first US institution of higher education to grant a bachelor's degree to an African American, graduating Alexander Twilight.[2]
John Neal publishes Seventy-Six, the first American work of fiction to include the phrase "son-of-a-bitch."[3]