While many of the most famous cavalry raids were launched by Confederate leaders such as JEB Stuart or Nathan Bedford Forrest, this was a Union raid. It was commanded by Benjamin Grierson, who despite pre-war dislike of horses quickly proved himself to be a brilliant cavalry commander.
His raid was part of U.S. Grant’s successful campaign against the Confederate stronghold of Vicksburg, on the Mississippi River. Grant’s infantry were marching down the west bank of the river, getting into a position from where they could cross over onto the east bank south of Vicksburg. Grierson was ordered to launch a raid through the heart of the state of Mississippi, to distract Confederate attention from Grant’s move, and force the Confederates to move troops away from the city.
Starting from La Grange, Tennessee, Grierson’s aim was to reach the Southern Railroad of Mississippi, and destroy as much of it as possible. From there he could either return to La Grange, or head south to the Union position at Baton Rouge, Louisiana. He started with three regiments, some 1,700 men. One of the reasons for his success was that he was willing to split this force. He began on 20 April, sending 175 men (what he called the “least effective portion of the command”) back to La Grange, with orders to make it look at if the entire expedition had returned.
After that he continued south, fighting a series of minor skirmishes (the Official Records list eleven), and avoiding any of the larger Confederate force chasing him. On 24 April the expedition reached the South Railroad, and did some considerable damage. Grierson now learnt that some large Confederate detachments were behind him, and decided to continue south to Baton Rouge. The journey continues as before. Small detachments confused Confederate attempts to find the main expedition, and on 2 May Greirson’s men reached safety at Baton Rouge.
Grierson’s men had marched 600 miles in 16 days. They had only lost three dead and seven wounded, as well as eight men who had to be left behind sick, and nine men missing. In his report Greirson claims to have killed and wounded 100 Confederates, captured 500, destroyed between 50 and 60 miles of railroad, destroyed over 3,000 stand of arms, and captured 1,000 horses and mules. At the end of the raid, Grierson was aware of at least 5,000 men who had been sent out to capture him. That included a considerable amount of Pemberton’s cavalry from Vicksburg, detached at a crucial moment, when they would have been better used to watch Grant on the Mississippi.
Grierson’s Raid was the most successful cavalry raid of the war for two reasons. First, it played a direct role in the success of the main expedition against Vicksburg. Many of the Confederate raids had no more than nuisance value. Stuart’s ride around McClellan’s army on the Peninsula in the previous year could claim a similar significance, playing a part in the defeat of that army. However, Grierson’s second achievement was to take a large cavalry force through entirely hostile territory in the heart of the Confederacy. Stuart had been operating in Virginia, while other Confederate cavalry raids were made in friendly parts of Kentucky and Tennessee. Grierson’s raid was an early example of the Union’s ability to bring the war to the heart of the Confederacy, to be repeated on a larger scale by Sherman in Georgia and the Carolinas over the next two years.