Read it through once

WE used to plow past the lofty hill-city, Vicksburg, down-stream; but we cannot do that now. A cut-off has made a country town of it, like Osceola, St. Genevieve, and several others. There is currentless water--also a big island--in front of Vicksburg now. You come down the river the other side of the island, then turn and come up to the town; that is, in high water: in low water you can't come up, but must land some distance below it.