This coming week we celebrate the 155th anniversary of the Battle of Gettysburg, the Civil War’s deadliest and most renowned battle. My innumerable visits over the years have formed an enduring admiration for those who fought there, as well as for an organization that has remained virtually unheralded.
The crucial Battle of Gettysburg took place on July 1, 2 and 3, 1863, following a month-long effort by Union Maj. Gen. Joseph Hooker’s Army of the Potomac to locate Confederate Gen. Robert E. Lee’s invading forces, the Army of Northern Virginia.
To the extent that the Union succeeded in piercing the Confederate veil of secrecy, much credit belongs to Hooker’s intelligence staff, Col. George H. Sharpe’s Bureau of Military Information (BMI).
President Abraham Lincoln had charged Hooker with tracking Lee and engaging his army in battle, while at the same time protecting the capital at Washington. Lincoln knew if Lee stole a march into the North unopposed, he could move across Pennsylvania and capture Harrisburg — and from there he could threaten Philadelphia, Baltimore and Washington.
Lee’s march began below the Rappahannock River in the area of Fredericksburg, Va., just south of Hooker’s forces located on the opposite side of the river. Lee’s plan was to cross westward through the Blue Ridge Mountains and move north into Maryland and Pennsylvania.
When Sharpe learned about a Rebel movement, he ordered Capt. John McEntee and several scouts to find out more about Lee’s plans. Once McEntee forwarded additional information to Sharpe demonstrating that Lee intended to invade the North, Hooker started moving the Union army away from Fredericksburg in pursuit and to protect Washington.
Lee made a mistake, however, by sending his cavalry, under Maj. Gen. Jeb Stuart, in one direction, and his infantry in another. Stuart’s cavalry was diverted while trying to take a shortcut through the widely-separated Union army defending the capital when a signal corps station atop Maryland Heights across from Harpers Ferry, W.Va., sent a message to Hooker that Lee’s army was crossing the Potomac at Shepherdstown.
As a result, Hooker ordered his army across the Potomac in pursuit, thereby blocking Stuart from passing through and forcing him to go around the previously stationary Union army. As Lee’s primary provider of information about the enemy, Stuart’s separation and late arrival at Gettysburg would limit Lee’s maneuverability and diminish his chances for victory.
When both armies reached Pennsylvania, they converged around a small crossroads town named Gettysburg. A battle erupted on the first day of July, and the Rebels gained the advantage after being able to bring a larger number of troops onto the field.
The next day, Lee remained on the offensive after the Rebels deployed on Seminary Ridge and the Yankees on Cemetery Ridge — separated by a about a mile and located just south of town. Lee attacked both Union flanks during the day and evening, with the outcome remaining a stalemate.
Sharpe informed Maj. Gen. George G. Meade (replacing Hooker, who resigned on July 28 after disagreeing with General-in-Chief Henry Halleck’s strategy) that Lee had used all of his combat units during the first two days of fighting, with the exception of the brigades of Maj. Gen. George Pickett’s division. The BMI had acquired this information through interrogation of numerous Rebel prisoners and deserters taken during the first two days of fighting.
Therefore, Meade held a meeting with his commanders on the evening of July 2 and decided to maintain the army’s defensive position on Cemetery Ridge and await an attack. On July 3, that attack came as the Union army held its ground and repulsed what became known as Pickett’s Charge, gaining a crucial victory at Gettysburg.
The BMI played a significant role in Lee’s defeat at Gettysburg, and Sharpe’s intelligence staff would continue to provide vital information to Union armies about the Confederate forces for the remainder of the war, while remaining out of the public eye.
Visitors to Gettysburg will learn much about the fighting that took place during the three-day battle. However, it is fitting to also know that the members of the Union intelligence staff known as the BMI are the unsung heroes of the Civil War’s most famous battle.
Tom Ryan is the author of the multiple award-winning “Spies, Scouts & Secrets in the Gettysburg Campaign” and “Essays on Delaware during the Civil War,” of which signed copies available at Bethany Beach Books, at Browseabout Books in Rehoboth Beach and at Allison’s Card Smart in Milford. Contact him at firstname.lastname@example.org or visit his website at www.tomryan-civilwar.com.
By Tom Ryan
Special to the Coastal Point