Battle of Marais des Cygnes The Battle of Marais des Cygnes took place on October 25 , 1864 , in Linn County , Kansas during Price ' s Missouri Raid in the American Civil War . It is also called the Battle of Osage , and the Battle of Trading Post . It proved to be the first of three interconnected actions on this same day , all involving elements of Major General Sterling Price ' s Confederate Army of Missouri and the Union ' s Provisional Cavalry Division commanded by Major General Alfred Pleasonton . During this battle , two brigades of Pleasonton ' s cavalry under Colonel s John F . Philips and Frederick Benteen caught up with Price ' s rear guard at Trading Post , Kansas , as it covered the crossing of the Marais des Cygnes River by the Southern supply train . Though unable to prevent the crossing or inflict serious damage on Confederate forces , Pleasonton ' s troopers did manage to capture 100 prisoners and two cannon , forcing Price to continue his retreat . This led in turn to a second engagement at Mine Creek later that morning , followed by a final battle at Marmiton River in the afternoon . The three Union victories won on this day sealed the fate of Price ' s campaign . Background . Major General Sterling Price had led an expedition into Missouri seeking to capture that state for the Confederacy , or at least to negatively affect Abraham Lincoln ' s chances for reelection in 1864 . After a series of several battles across that state , Union forces under Major Generals Samuel R . Curtis and Alfred Pleasonton finally defeated Price decisively at the Battle of Westport , in modern Kansas City , Missouri . Price withdrew south toward his base in Arkansas while Pleasonton , commanding a Union cavalry division , pursued him into Kansas hoping to capture or destroy his army before he could reach Confederate territory . Battle . General Price ' s retreating army was hampered by the presence of a rather large supply train , containing upwards of 500 wagons partly filled with desperately needed war supplies for the South . Coming to the Marias des Cygnes River , near a place called Trading Post , Price decided to camp along a ford in pouring rain . Hard on his heels , Pleasanton ' s cavalry reached Price ' s encampment early on the morning of October 25 . At 4am , his artillery opened fire , followed by a furious Union attack . Price ordered his troops to cross the river immediately , leaving Brigadier General James Fagan to hold the attacking Federals back until he could extract his wagon train . According to one account , the Confederates abandoned their camp so rapidly that attacking Union cavalrymen came upon campfires with meat still cooking on spits above them . Confederate rifle fire was mostly ineffective , as the Southerners were camped on a high ridge about two - hundred feet above the approaching Federals , and their shots mostly sailed over the attackers ' heads . Although the Northerners were unable to prevent Price ' s rearguard from crossing the river , they did capture about one hundred prisoners and two cannon . Undaunted , the Federals continued across the Marais des Cygnes in pursuit of Price , though this was delayed due to the rain and swollen condition of the river . Little girl lost . William Forse Scott , a Union participant in the battle , wrote in " The Story of a Cavalry Regiment : the Career of the Fourth Iowa Veteran Volunteers " that as he and other cavalrymen were crossing the field adjacent to the Confederate encampment ( having just driven the Rebels across the Marais des Cygnes moments before ) , they came across a terrified six - year - old girl hiding in some grass . She was clutching a schoolbook , and had apparently become lost while trying to avoid the Southern soldiers camping near her home the night before . Amazingly , she had been lying between the attacking Federals and Price ' s force , but was unhurt and undiscovered until Scott stumbled upon her . The girl , whom Scott did not name , was taken to the nearest house and turned over to the occupants after assuring Scott and his companions that she could make her way home from there . Aftermath . About six miles south of the battle site , Colonels John Phillips and Frederick Benteen , commanding Pleasanton ' s two cavalry brigades at the Marias des Cygnes engagement , caught up with Price ' s wagon train as it struggled to cross Mine Creek . The resulting Battle of Mine Creek would prove to be one of the largest cavalry engagements of the entire Civil War , resulting in the loss of two Rebel generals , and a significant portion of Price ' s train .