The purpose of a model is to take a complex, real-world situation and pare it down to the essentials. If designed well, a model can give the analyst a better understanding of the situation and any related problems. A good model is simple enough to be understood while complex enough to capture key information.
I hope this helps (if it did pls mark as brainest)
Pls have a beautiful and wonderful day
Heres my guesses.
1. the river was too rapid and the soldiers would get flushed away
2. it flooded?
3. they lacked the utilities to cross the river
4. keep in mind vicksburg is in mississippi so they might have been confronted with a wide river.
5. lack of soldiers?