August 17, 1862: Gideon Welles enters into his diary a tantalizing sentence: “But Stanton is so absorbed in his scheme to get rid of McClellan that other and more important matters are neglected.”
Edwin Stanton, the Union’s Secretary of War, plotted against General George McClellan, Union commander of the Army of the Potomac!
“There were two wars going on 1861-1865 – the military war and the political war. They are bound together in a conspiracy which nearly won the war for the Confederacy.” (Gerald R. Hibbs. Review at amazon.com of “The Dark Intrigue”, by Frank van der Linden)
General George McClellan had asked Allan Pinkerton to organize a Secret Service Department for his army. This was done and its headquarters was in Cincinnati, Ohio. Although General McClellan is usually remembered negatively, there has been some reassessment lately. A scholarly counter-opinion exists that McClellan was in fact “a great general who had been underestimated.” (Mackay, James. Allan Pinkerton: The First Private Eye. Wiley & Sons, 1997)
Allan Pinkerton later relocated his secret service headquarters to Washington, DC. “This was the first real organization of the secret service,” wrote Pinkerton in his book, The Spy of the Rebellion. “How much benefit was rendered to the country by this branch of the army will probably never be known — the destruction of nearly all my papers in the great fire of Chicago  preventing their full publication…”
“There can be no doubt of the fact,” revealed Pinkerton (Spy of the Rebellion), “that the young commander-in-chief [McClellan] was subjected to the persecutions of the most malignant political intriguers, who feared that his growing popularity would result in political exaltation. Taking advantage of the fact, therefore, that General McClellan was an avowed Democrat, a scheming cabal was working to weaken his influence with the people by vague insinuations against his loyalty to the Union cause. To further that end, his plans, so carefully and intelligently matured, for the speedy crushing of the rebellion, were either totally disregarded by an unfriendly cabinet, or were so frequently thwarted, that to successfully carry them out was an utter impossibility.”
The great Otto Eisenschiml confirmed: “Against McClellan alone, of all his generals, Lincoln, under the influence of [Edwin] Stanton’s intrigues, showed a strange and only thinly veiled animosity.” (Why Was Lincoln Murdered? 1937)
Eisenschiml devoted an entire chapter (“Not Wanted – Victory in the East”) of his book (Why Was Lincoln Murdered?), to the political underminings of McClellan’s efforts. Abraham Lincoln had once famously said about McClellan, “He has got the slows.” But Old Abe forgot to mention that he himself had wired McClellan with advice to “move cautiously and safely.”
By the time Edwin Stanton’s intrigues helped finally remove McClellan from command in November 1862, Allan Pinkerton, McClellan’s partner, was in a weak position and he went too. In the place of Pinkerton as head of the Secret Service, Stanton put in his man, Colonel Lafayette Baker.
So Edwin Stanton, via intrigue, had increased his domain to include the Union’s secret police. Stanton tried also to usurp the domain of Gideon Welles, Secretary of the Navy, but Welles successfully resisted the encroachment. (Background: “Seward Was Captain Binghamton”, Ersjdamoo’s Blog entry of March 25, 2013)
Eventually, Stanton’s lust for power went so far as to enable the elimination of the chief executive, Abraham Lincoln, on April 14, 1865.