Within a year of the beginning of the Civil War, Union ships had effectively blockaded most of the Confederate ports from Virginia to Florida to Louisiana. The Confederacy was now relying on bringing in needed foreign goods to Texas and then transporting them into the South across the Mississippi river, along with other valuable supplies from Texas including beef and lead from Missouri.
Consequently, the Union set its sights on controlling the Mississippi River and cutting off their needed supplies and ability to transport troops from one location to another. One of the first Union objectives was to capture New Orleans and control the mouth of the Mississippi River.
On April 29, 1862, Union Naval Captain David Farragut, accomplished the capture of New Orleans, giving the Union control of the southern entrance to the river. They also controlled the northern end of the river in Union territory and began to squeeze both ends.
In late 1862, Union General Ulysses S. Grant had set his sights on capturing Vicksburg, Mississippi. The city was a key Confederate stronghold on the Mississippi River, located about 200 miles by land or 250 miles via the river south of Memphis and about 150 miles by land or 180 via the river north of Baton Rouge. Taking Vicksburg would give Grant strategic access to attack a number of Confederate targets.
The Union controlled the Mississippi River north of Vicksburg and south of Port Hudson. The Confederates controlled the 160 miles of river between the two Confederate strongholds. If the Union could take Vicksburg, they would essentially have control of the entire Mississippi River except for Port Hudson, cutting off their vital supply lines.
For six months Grant had been unsuccessful in his attempts to take Vicksburg. He sent General William T. Sherman to take Vicksburg, but the attempt failed. In early 1863, Grant devised a plan to sail his army down the Mississippi River along the bank opposite of Vicksburg. Once south of Vicksburg, the Union forces were then to cross back over the river and launch their attack on Vicksburg from the east. Grant turned to Union Admiral David Dixon Porter to help ferry some of his troops and important supplies south past Vicksburg.
On April 16, 1863, under cover of darkness, Porter led a flotilla of 12 ships with barges down the Mississippi River past Vicksburg and its battery of guns. Using steam powered paddle wheelers, Porter knew the troops at Vicksburg would easily hear them approaching. To help muffle the sound, he had the exhausts of the steam engines re-routed into the paddle wheel housing. He then stacked bales of cotton on the decks facing the Vicksburg guns in hopes of them adding some extra protection. Lastly, he had the ships lined up off center from each in case one got hit and sunk, the others could still pass by.
However, the Confederates spotted Porter’s fleet. Some of them rowed to the western side of the Mississippi River where they set fire to trees in order to provide a backlight for the Confederate guns. The Confederates opened fire on Porter’s fleet which took over two hours to pass the fortifications. In the end, Porter lost 1 ship and 2 barges, but the rest of the fleet successfully passed on south of Vicksburg, helping to set up the upcoming siege.
The bulk of Grant’s forces were on the west side of the Mississippi when Porter’s fleet managed to sail south of Vicksburg. Porter then helped Grant ferry his troops across the river and into Mississippi. Grant planned to march north to Vicksburg, believing it to be the city’s weaker area, but before he could launch the attack, he ended up dividing his forces to stave off an assault from the east by Confederate General Joseph Johnson.
Johnson took up position in Jackson, Mississippi, the state capital located about 40 miles east of Vicksburg. Eventually, Johnson was defeated and Jackson was captured by part of Grant’s forces.
On May 16, 1863, Confederate General John Pemberton tried to stop Grant’s forces at Champion Hill, but Grant’s forces prevailed, driving Pemberton back to Vicksburg.
On this day, May 18, 1863, Union General Ulysses Grant laid siege to Vicksburg. His forces had the city surrounded on land and on the river. The Union troops dug defensive trenches and siege lines and set up their artillery. The siege of Vicksburg would last a month and half, ending with the surrender of the Confederate troops on July 4, 1863.
For a more detailed account of the events leading up and including the siege of Vicksburg, I strongly urge you to watch the video below.
Sources for the above includes: Vicksburg; Vicksburg During the Civil War (1862-1863): A Campaign; A Siege; The Siege of Vicksburg Commences; Vicksburg Campaign; General Ulysses S. Grant Attempted to Take Vicksburg, Mississippi May 19, 1863; Vicksburg: Civil War Mississippi; Today, April 16, 1863: A Small Event That Lead to A Bigger Victory; Today, April 29, 1862: Union Captures Gateway to Mississippi River.