at night in april of 1863 there are casualties and the guns take a toll little bit, admiral david dixon porter, marvelous character and superior naval man pulls it off, gets a lot of his gun boats and a bunch of supply barges and they run it in the middle of the night and get past the guns enabling grant to come across the river and make it across the mississippi, no one in vicksburg expects that and the townspeople aren't even really aware of it because the rumors that are flying through the confederate army that grand is leaving, they are retreating, union controls waters, so the word flyers that the recent you see across the river, the louisiana side, you see all these union troops marching south, the reason you see that, they are leaving, they're running away. the people want to believe that, they convince themselves of that. they have no reason to leave vicksburg. after the battle of the big black river when the union gunboats begin to shell the town of vicksburg all-day and all-night, all that wonderful confederate army goes out to meet ulysses grant and they're going to shove grant out