Most of the focus will be on a small town in South Central Pennsylvania. What happened there is significant and fascinating, but generally it is overemphasized at the expense of the real action.
In the western theater, forces under General Grant had successfully executed his novel campaign plan, with the result that he had Confederate forces under siege in Vicksburg Mississippi, and the Confederacy was about to be split in two as the Federal government gained complete control over the Mississippi River. Arguably this was far more important to the course of the war than what happened at Gettysburg.
Vicksburg
By July 1st, Grant's brilliant campaign had settled into a siege. The defenders of Vicksburg had no way out and it was only a matter of time until they ran out of supplies. This moment would be coming soon. In addition to splitting the Confederacy, Grant & Sherman would also start to set a pattern for future operations that would carry through Sherman's march through Georgia in 1865. The pattern? Unable to occupy Jackson Mississippi, Grant would send Sherman to raid Jackson instead, and Sherman would destroy the railroads, the warehouses and the factories, leaving nothing in Jackson of value to the Confederacy.
Gettysburg
The events of the first day are only partly described in the film. The film omits entirely the intense fighting on the west side of the town which lasted until the two Federal Corps were overwhelmed by Confederates coming from the west and the north. The Federal forces would stream through the town and settle on Cemetery Hill, where the remainder of the Army of the Potomac would arrive for the second day's battle.
