During the winter of 1862-1863, Union Major General Ulysses S. Grant made several unsuccessful forays to capture the strategic fortress city of Vicksburg, Mississippi.
A combination of swampy bogs along the Yazoo River north of the city, the 200-foot-high bluffs fringing the river west of the city, determined Confederate resistanc
e, and rebel cavalry raids along his lines of communication thwarted Grant’s every attempt to seize the “Gibraltar of the Confederacy.”
In March 1863, Grant proposed a bold stroke to circumvent Vicksburg’s natural obstacles and Confederate fortifications.
He ordered his army to march south of Vicksburg on the west side of the Mississippi and sent Rear Admiral David D. Porter’s supporting flotilla past the citadel’s batteries to rendezvous with his forces south of Vicksburg.
To disrupt rebel communications east of Vicksburg, he sent Colonel Benjamin H. Grierson’s 1,700 cavalrymen on a lengthy raid from La Grange to Baton Rouge, Louisiana.
The complete story at the source below.