On May 23, 1863, the siege of Vicksburg began.
Union forces under the command of Gen. Ulysses S. Grant settled down to a siege of Vicksburg, Miss., on the Mississippi River. Seven regiments of infantry and two batteries of artillery from Michigan participated in the six-week siege of the Confederate stronghold.
Michigan History magazine
Here’s Why the Battle of Vicksburg Was So Important. Smithsonian Channel.
Animated Battle of Vicksburg. Civil War Trust.