Factual error: Towards the end when the cavalry uncovers the American flag, it has 50 stars.
Factual error: The train that pulls into Newton Station with Confederate soldiers has freight cars of modern construction. This can be seen by the newer type trucks, unlike the 'arch-bar' trucks of the period.
Factual error: The movie takes place in 1863, however, the Union cavalry troops are equipped with Springfield "Trapdoor" carbines, a weapon not introduced until 1873.
Factual error: The Confederate deserters played by Denver Pyle and Strother Martin claim to be from the 10th Georgia Infantry. This is unlikely in the summer of 1863 because it was part of Semmes' brigade of Longstreet's Corps of the Army of Northern Virginia at that time and was campaigning in Pennsylvania-or, depending upon when the movie is supposed to have taken place, recovering from its losses at Gettysburg. Certainly it was no where near Mississippi.
Factual error: The movie takes place before the fall of Vicksburg which happened on July 4, 1863. Yet at the beginning of the movie there are two references to Andersonville (Camp Sumter), the notorious Confederate prison in Georgia. Andersonville did not receive its first prisoners until February, 1864.