After working as a farmer in Long Island and a railroad official in Chicago, he voluntarily returned to military service and served as a Union Army Colonel during the American Civil War.

He was court-martialed for allowing the 19th Illinois Infantry Regiment, in retaliation for Alabama civilians firing upon his troops during their earlier retreat from the town, to unleash total war in the 1862 "Sack of Athens".

During his 1862 court-martial, Turchin complained that the United States Army had as yet no equivalent to the "État Major" and that he was accordingly, "forced to do such staff work himself, which left him little time to attend to peripheral matters".

[10] The Turchins' reasons for emigration to the United States remain uncertain, but are believed by some scholars to have been connected to a secret belief in liberal democracy and representative government and possibly also, given his later policy of protecting runaway slaves during the American Civil War, to a likely hostility to serfdom in Russia.

If so, these would not have been acceptable positions, particularly following the Decembrist revolt, for any Russian subject, no matter what their place in the class system, to hold during the reign of Tsar Nicholas I of Russia.

[14] Intriguingly, in one letter following his emigration, Turchin wrote, "I thank America for one thing, it helped me get rid of my aristocratic prejudices, and it reduced me to the rank of a mere mortal.

I fear no work; no sphere of business scares me away, and no social position will put me down; it makes no difference whether I plow and cart manure or sit in a richly decorated room and discuss astronomy with the great scholars of the New World.

Historian Thomas Lowry has written of Turchin, "He used European methods of discipline with his troops, which soon produced an efficient and tightly run fighting unit.

"[16] Turchin wrote on July 30, 1862, "The more lenient we are to secessionists, the bolder they become and if we do not prosecute this war with vigor, using all the means we possess against the enemy, including the emancipation of the slaves, the ruin of the country is inevitable.

"[17] Having led his regiment in Missouri and Kentucky, he soon found his unit under the command of Major General Don Carlos Buell in the newly organized Army of the Ohio.

Frustration had been building among these Union soldiers for weeks over repeated attacks and Buell's clearly stated conciliatory policy of protecting the rights and property of Southerners.

The reported involvement of local citizens in the rout at Athens and the humiliation suffered by the Union soldiers led to the sacking of the town when Turchin brought up reinforcements.

[18] General Joseph Keifer, who served as an ad hoc judge advocate, stated "Turchin did not believe that war could be successfully waged by an invading army with its officers and soldiers acting as missionaries of mercy.

Also, as Kastenberg points out, Brigadier General James Garfield wrote to Secretary of War Edwin Stanton, "I cannot sufficiently give utterance to my horror of the ravages, outrages, that have been committed... this town was, by Col Turchin, given up to pillage."

[19] According to the recitations, there were over twenty or so instances in which Turchin supposedly ordered his soldiers to pillage and plunder Athens, Alabama, without any proper restraints to them.

Rather than the courtly fictions of Sir Walter Scott, with their intimations of chivalry and gracious treatment of professed non-combatants, Turchin's eye viewed the civilian secessionists as traitors, grist for the mills of more hardheaded conquerors such as Genghis Khan, Tamerlane, and Ivan the Terrible.

It is obvious that Turchin had little use for Victorian sentimentality towards the vanquished Rebels, who fired on his troops and then retreated to the sanctuary of their parlors to complain of soiled carpets.

The court sentenced him to a dishonorable discharge from the United States Army, but the judges, who clearly thought that Turchin was far too valuable of a fighting commander to be permanently sidelined during wartime, all signed a statement requesting that their superiors overturn the verdict.

He distinguished himself during the battles of Chickamauga, for which he dubbed, "the Russian Thunderbolt", and Chattanooga, and in the Atlanta Campaign, during which his commanding officer, Absalom Baird, praised Turchin's, "soldiery and patriotic" performance.

[31][32] Even though his orders were issued in retaliation for illegal civilian warfare against his troops, John Turchin has long been portrayed by Neo-Confederates and other adherents of the Myth of the Lost Cause as a irredeemably villainous figure for the so-called "Rape of Athens," and Lincoln has traditionally been reviled in the same circles for reversing his court-martial verdict.

Turchin's actions at Athens, though, presaged those that other Union commanders, particularly William Tecumseh Sherman, would adopt in prosecuting total war against the Confederate States.

Davis' authorisation for total war also resulted in the Charleston Riot, the conspiracy to burn down New York City, the St Albans, Vermont bank robbery and arson attack, the conspiracy to commit piracy on the Great Lakes masterminded by John Yates Beall, and many other similarly ungentlemanly acts of warfare to be unleashed behind Union lines.