The Battle of Marais des Cygnes was a battle during Price's Missouri Raid in the American Civil War. It happened on October 25, 1864, in Linn County, Kansas. It is also called the Battle of Osage, or the Battle of Trading Post. It was the first of three related actions on the same day. All three of those actions involved elements of Major General Sterling Price's Confederate Army of Missouri, and the Union's Provisional Cavalry Division commanded by Major General Alfred Pleasonton.