Did you put up any interpretive markes indicating that Grant's movement overland had already been defeated by Lincoln, Halleck, and McClernand?

:D

Dec. 4th, Grant to Halleck --
How far south would you like me to go? ... with my present force it
would not be safe to go beyond Grenada ...

Dec. 5th, Halleck to Grant --
... you should not attempt to hold the country south of the
Tallahatchie ... your main object should be to hold the line from
Memphis to Corinth with as small a force as possible, while the
largest number possible is thrown upon Vicksburg with the gunboats.