Vicksburg and Gettysburg

I love the mini series and the story, but there is one problem I saw . The battle of Gettysburg was July 1-3, 1863, Vicksburg surrendered the a siege to Grant July 3 , 1863. The portrayal was before , even the Gettysburg address was shown to be before.
I grew up 90 miles from Vicksburg and have toured that old city many times . The battlefield and courthouse hold many stories.
My great uncle is buried in the city cemetery in the confederate section, he died a little before the siege started .