Out of 2.75 million soldiers, over 400,000 were taken prisoner during the Civil War, some of them several times, and prison conditions were so harsh over 56,000 perished in captivity. The worst was Andersonville, where 39% who walked in, never walked out.
Belle Isle, a 54-acre island in the James River, had been home to a nail factory, but since it was surrounded by rapids and close to railway tracks, it was deemed ideal as a holding pen for Union prisoners awaiting transfer home. Belle Island was reserved for enlisted men as officers were held at Libby Prison. After both sides became depleted, they agreed to swap prisoners. A rickety footbridge provided access to the railway line.
Belle Isle had no barracks and the flimsy tents were severely overcrowded once exchanges were scrapped. The War Department had decided returning Confederate soldiers to the front was keeping the rebellion fires burning, so they abruptly broke off the Dix-Hill cartel and halted all swaps in June of 1863, which caused the population at Belle Isle to swell immediately. The situation was compounded by the refusal of the Confederacy to accept one-to-one swaps involving blacks. During the winter of 1863-64, as many as 1,500 a week were perishing at Belle Isle.
In a New York Tribune article dated January 25th, 1864, Charles Dunham, posing as Sanford Conover, exposed a plot by the villainous Colonel George Margrave to capture and assassinate President Lincoln. In fact, the dastardly Colonel Margrave was a figment of Dunham’s imagination, as was the kidnap and possible assassination plot hinted at in his article. Conover promised additional details would be forthcoming very soon. That never happened.
Dunham is the most mysterious character operating on both sides during the Civil War from his perch in New York City, a city that was largely pro-Confederate. He might write an article for a Union paper one day, and then attack the article in a Copperhead newspaper under a different byline. In four months, Dunham would be put in charge of bribing and coaching witnesses for the military tribunal that hanged poor Mary Surratt and three others, a list that included his wife, mother-in-law and brother-in-law. Most of the testimony presented to the tribunal was fabricated.
Dunham’s fake news succeeded in raising significant alarm bells in Washington. Within days, Secretary of War Edwin Stanton and President Abraham Lincoln were discussing plans for a raid into Richmond to release the thousands of prisoners at Belle Isle, a project initially suggested by Major General Benjamin F. Butler. Butler also wanted to destroy the Tredegar Iron Works and kidnap Jefferson Davis as part of the mission. Butler got approval for the raid and it was scheduled for February 7. However, the Confederates were warned ahead of time and Butler’s cavalry assault turned back before getting near Richmond.
A week later, Brigadier General Judson Kilpatrick secured a private meeting with Lincoln, something allegedly arranged through the assistance of a Republican Senator. Nicknamed “Kill Cavalry” by his own troops, Kilpatrick was already legendary for mounting reckless frontal assaults. He had circumvented military protocol by seeking this private meeting. Aside from freeing Belle Isle and Libby prisons, Kilpatrick suggested severing Confederate lines of communication. Lincoln also wanted his recent amnesty proposal circulated behind enemy lines. Kilpatrick was directed to the War Department to work out details with Stanton. On February 16, Stanton approved the raid and its three objectives.
General Meade and the head of the Cavalry Corps. Major General Alfred Pleasonton went on record opposing the raid. Meade distanced himself in his written orders to Kilpatrick: “No detailed instructions are given you, since the plan of your operations has been proposed by you with the sanction of the President and Secretary of War.”
Ulric Dahlgren was an ambitious 21-year-old who’d recently lost a leg below the knee at the Battle of Gettysburg. His father was commander of the South Atlantic Blockading Squadron and close friends with Lincoln, which is why Dahlgren had advanced so rapidly to colonel, despite a total lack of command experience. However, when Dahlgren arrived at Kilpatrick’s seeking a job now that his leg had healed, he was offered command of the raiding party and given secret orders.
On March 2, Dahlgren was killed outside Richmond near King and Queen County Courthouse. William Littlepage, age 13, was rifling through his pockets, looking for valuables, when he discovered a packet of documents, which he dutifully handed over to the commander of the home guard, who forwarded the notebook and papers to Jefferson Davis. According to the documents, after freeing the Union prisoners, Ulric was to torch Richmond and assassinate Davis and his entire cabinet if possible. The fact Dahlgren had not destroyed these incriminating orders but allowed them to be captured was evidence of his lack of experience.
The documents were circulated to newspapers in hopes of winning sympathy and drawing a foreign power into an alliance with the Confederacy, as well as strengthening the anti-war Copperhead movement opposing the Radical Republicans.
The War Department immediately claimed the papers were forgeries, but that was undoubtedly a lie because they were written on official stationary, although strangely unsigned by any authority, probably due to the extreme nature of the mission. It’s not clear who dreamed up the assassination scheme, although it seems likely Stanton was doing this on his own initiative. Dunham seems to have been one of Stanton’s counterintelligence operatives, and by seeding a fake story of a Confederate assassination plot against Lincoln, he had opened a door for Stanton to launch a similar plot against Davis.
The Dahlgren affair is likely what caused Colonel John S. Mosby to begin formulating his own plan to kidnap Lincoln in revenge and swap him for all the Confederate prisoners in Union jails. For this delicate mission, Mosby would risk exposing his greatest asset in Washington, John Wilkes Booth, who had wormed his way into the Radical Republican cabal by dating the daughter of a Senator. After a trip to New York City, Booth was soon in motion on the kidnap plot, aided by the arrival of Mosby’s chief enforcer. But the kidnap was exposed by Union double agents, and the plot twisted to murder by powerful forces that wanted Lincoln removed. They had hoped Salmon Chase would replace Lincoln, but after Lincoln won a second term, a murder plan was put into action.
Is it worth mentioning that right after the war, Stanton ordered all Confederate archives shipped to the War Department, specifically requesting the Dahlgren documents be sent direct to his office? Those documents have never been seen since.