Cavalry Corps ( Union Army ) Two corps of the Union Army were called Cavalry Corps during the American Civil War . One served with the Army of the Potomac ; the other served in the various armies of the West . Overview . In contrast to the Confederacy , which early on spawned such brilliant cavalry leaders as J . E . B . Stuart , Nathan B . Forrest , and John S . Mosby , the Union high command initially failed to understand the proper way to use cavalry during the early stages of the war . At the time , cavalry units in the Union armies were generally directly attached to infantry corps , divisions , and " wings " to be used as " shock troops , " and essentially played minimal roles in early Civil War campaigns . The Union cavalry was disgraced by Stuart ' s raids during the Peninsular , Northern Virginia , and Maryland Campaign s , where Stuart was able to ride around the Union Army of the Potomac with feeble resistance from the scant Federal cavalry . The Federals rarely even used cavalry as scouts or raiders in the early days of the war . Only a handful of Union cavalry officers , George Bayard , Benjamin Grierson , and John Buford among them , distinguished themselves in a positive way in the first two years of the war . Cavalry Corps , Army of the Potomac . After the disastrous Fredericksburg Campaign , Maj . Gen . Joseph Hooker took command of the Army of the Potomac . One of Hooker ' s positive contributions was in creating a unified cavalry command in April 1863 . Other than at Antietam , where the cavalry had been combined into a single division for a planned ( but unengaged ) attack on Lee ' s center , the Union cavalry had not been unified to date . Hooker organized three previously unrelated divisions into a single corps of cavalry , placing it under the unified command of George Stoneman . Hooker also began outfitting them with Sharps and Smith breechloading rifles , and , in a couple cases , with Spencer repeating rifle s , giving them an advantage in firepower over the Confederates . Chancellorsville . Despite Hooker ' s organizational changes , the new Cavalry Corps gave a poor accounting of itself during the Chancellorsville Campaign . Hooker ordered Stoneman to launch a diversionary raid against Richmond to distract Stuart ' s cavalry , but the raid was unsuccessful , resulting in the debacle at Kelly ' s Ford — an indecisive battle that forced the raid ' s premature abortion . Worse , Hooker kept only a single division — under Alfred Pleasonton — with the main army to use as scouts or screens while traveling through the dense " Wilderness , " accounting in part for the success of Stonewall Jackson ' s famous flank march on May 2 . Gettysburg . Stoneman and division commander William W . Averell were sacked after Chancellorsville , and replaced , respectively , by Alfred Pleasonton and David McM . Gregg . During the early stages of the Gettysburg Campaign , the cavalry first gained notice and respect from their Confederate foes at the Battle of Brandy Station , on June 9 , 1863 — the largest primarily cavalry engagement ever fought on the American continent . Though Pleasonton ' s men were ultimately defeated , this battle established the Union cavalry as no longer inefficient and overmatched , but a foe to be reckoned with . Numerous other changes were made in brigade command as the campaign progressed , and a number of young officers were promoted to brigade command , including Wesley Merritt , George Armstrong Custer , and Elon J . Farnsworth . Later in the campaign , Judson Kilpatrick ' s division , sent from the XXII Corps , joined up with the army . The cavalry divisions engaged Stuart in a number of fierce , hotly contested battles at Aldie , Middleburg , Upperville , Hanover , and several smaller engagements . It was John Buford ' s cavalry division which touched off the Battle of Gettysburg itself , engaging the Confederate division of Henry Heth to prevent him from occupying Gettysburg on July 1 . Buford ' s troopers played a major part in slowing Heth ' s initial advance , and , after being relieved by infantry , spent the rest of July 1 screening and scouting . His division was sent to guard the army ' s supply trains for the remainder of the battle , but the divisions of Gregg and Kilpatrick remained on the field . On July 3 , concurrent with Pickett ' s Charge , Gregg ' s division ( with Custer ' s brigade of Kilpatrick ' s division ) engaged Stuart east of Gettysburg and checked repeated Confederate advances . However , on the same day south of Gettysburg , Kilpatrick ordered a futile charge by the brigade of Elon J . Farnsworth against Confederate positions on Big Round Top , resulting in Farnsworth ' s death and heavy casualties among his men . The cavalry continued to perform aggressively in George Meade ' s pursuit of Lee into Virginia . In an irony , the last battle of the campaign , at Falling Waters , occurred between the remnants of Heth ' s and Buford ' s divisions . 1864 . If any doubts remained as to the Union cavalry ' s equality with its Southern counterparts , they were dispelled during Ulysses S . Grant ' s Overland Campaign . The Cavalry Corps , now consisting of four divisions , was placed under command of the fiery Phillip Sheridan . In the early stages of the campaign , they engaged Stuart ' s cavalry in a series of ferocious , bloody battles , killing General Stuart at Yellow Tavern . Stuart ' s successor , Wade Hampton , proved to be an equally formidable foe at the battles of Haw ' s Shop , Old Church , Trevilian Station , and Battle of Saint Mary ' s Church . The Union cavalry spent most of the Petersburg Campaign trying to cut rail lines from Petersburg and Richmond . The bulk of the cavalry was sent under Sheridan to join the Army of the Shenandoah during Sheridan ' s campaign against Jubal Early in the summer of 1864 ( see Valley Campaigns of 1864 ) . After Sheridan ' s highly successful campaign concluded , the cavalry corps — along with the rest of his army — returned to join the Army of the Potomac . For the next several months , they resumed their slow but steady snipping off of Confederate supply and communication lines . End of the war . The most conspicuous part played by the cavalry during the closing days of the war occurred in the week of March 25 – April 1 , 1865 , when Lee , in a series of bold but understrength and futile counterattacks , tried to break through the Union lines at Fort Stedman . The IX Corps repulsed the attack . A week later , at Five Forks , Sheridan ' s cavalry played a decisive role in repulsing George Pickett ' s last desperate attack and routing his division . Sheridan and his men continued to play a major part in harassing Lee ' s army as it withdrew to Appomattox Court House . In the last battles fought in Virginia , it engaged Confederate cavalry in a desultory skirmish at Appomattox Station on April 8 , and took part in a small skirmish the following day at the Battle of Appomattox Courthouse , which effectively concluded the war in Virginia . Western Cavalry Corps . As in the East , the various Union commanders in the West generally used cavalry poorly during the first two years of the war ; cavalry was again parcelled out to be attached to infantry corps as " shock troops " and scouts . Unlike in the East , where the cavalry proved itself the equal of its foes by the summer of 1863 , the Union cavalry in the West struggled to identify an equal to Nathan B . Forrest , and were defeated in most of their major engagements . Benjamin Grierson ' s famous raid during the Vicksburg Campaign was an aberration and far from the norm . The first attempt at a unified cavalry command occurred in late 1862 / 63 , when William S . Rosecrans , commanding the Army of the Cumberland , organized all of his cavalry into a single division , acting as a separate command from the infantry , under the command of David S . Stanley . This new division fought respectably , if unremarkably , at Stones River . During the Tullahoma Campaign this cavalry division was expanded to corps size . Stanley commanded the corps with Robert B . Mitchell and John B . Turchin commanding the 1st and 2nd Divisions respectively . Mitchell commanded the corps at Chickamauga while Edward M . McCook and George Crook commanded the divisions . During the Atlanta Campaign , General William T . Sherman reorganized the cavalry of the armies of the Cumberland and Tennessee into four " columns " , with no overall commander . ( These individual columns were commanded by Stoneman , Kilpatrick , Edward McCook , and Israel Garrard . ) The cavalry continued to perform in a mediocre - at - best fashion , failing an abortive raid to free Andersonville prison camp and being repeatedly defeated by Joseph Wheeler ' s Confederate cavalry in a series of fights in central Georgia . During Sherman ' s March to the Sea , Kilpatrick ' s division remained with the army , serving again with a lack of real distinction , while the rest of the cavalry went north with George Thomas to repel John B . Hood ' s invasion of Tennessee , taking part in the actions at Spring Hill and Murfreesboro . In December 1864 , just before the Battle of Nashville , a formal cavalry corps was finally organized , under Brevet Maj . Gen . James H . Wilson . It performed decently at Nashville , but , as before , failed to distinguish itself to any real degree . Wilson led the corps in one of the final battles of the war April 16 , 1865 , at the Battle of Columbus , where , fighting dismounted against Forrest ' s troopers , they were able to defeat their enemy – the only time Federal cavalry defeated General Forrest . The rest of the Union armies typically had no unified cavalry commands as such , other than a corps - sized command , under Pleasonton , that was briefly organized by the Department of Missouri to defend that state against Sterling Price ' s expedition in 1864 .