Itís 1862 and the pro-Confederate Bushwhackers are engaging in guerilla warfare along the Kansas/Missouri border against Union forces. Jack Bull Chiles (SKEET ULRICH) and Jake Roedel (TOBEY MAGUIRE) are childhood friends who support the Bushwhackers, despite Jake being a German immigrant whose father is decidedly pro-Union.
Nonetheless, after Jayhawkers murder Chilesí father, the two young men join a band of such guerilla fighters. Led by Black John (JAMES CAVIEZEL), Roedel and Chiles, along with fellow Bushwhackers Pitt Mackeson (JONATHAN RHYS MEYERS), Turner Rawls (MATTHEW FABER), George Clyde (SIMON BAKER) and his former slave, Daniel Holt (JEFFREY WRIGHT), set out to disrupt the Union activities and consequently get into several lethal encounters with them.
As winter sets in, the Bushwhackers disband into smaller groups, with Roedel, Chiles, George and Holt setting up a primitive camp on the outskirts of property owned by Mr. Evans (ZACH GRENIER). There, and only when there are no signs of feds in the area, does Brownís widowed daughter-in-law, Sue Lee Shelley (JEWEL), bring food to the men. While George goes off to stay with a lady friend of his, Chiles and Sue Lee begin a brief romance.
Yet with the arrival of spring and more fighting that whittles down their numbers, the Bushwhackers continue on their quest to insure the freedom of their way of life. After both Roedel and Holtís subsequent injuries lay them up at the home of Orton Brown (TOM WILKINSON), the men must determine their stake in the war while dealing not only with Sue Lee whom they earlier dropped off there, but as well as with Mackeson who has a personal vendetta against Roedel for earlier preventing more war-related atrocities.