Karl Anschütz was born in Zella-Mehlis, Thüringen, Germany, on August 24, 1840, and in 1852 emigrated to the United States with his parents, Georg and Elizabeth (Barthelmes), his brothers Anton (b. 1845), Reinhold (b. 1847), Johannes (b. 1849), and Eduard (b. 1851), and sister Christiane (b. 1838). During the ocean crossing, Georg was stricken with blindness, and never again regained his sight. The older Anschütz boys were therefore put into the position of having to support the family, which they apparently did quite well. The family ran a prosperous farm near Saginaw, Michigan, but in 1865, they moved to East Tawas, Michigan, where members of the family still reside.
On November 8, 1861, Karl Anschütz enlisted for three years' duty in Company C of the 15th Michigan Infantry at Detroit, mustering in to the federal service on December 24th. The regiment prepared for active duty at Fort Wayne, and after a languorous winter, they were thrust suddenly into the thick of the conflict, joining Grant's Army of the West shortly before the Battle of Shiloh late in March, 1862. During the battle, Anschütz reported, the regiment was unduly exposed to fire due to poor generalship, sustaining 97 casualties as a result, including 33 deaths. Taking no time to heal their wounds, the regiment pursued the Confederate army to Corinth, Mississippi, where they remained for several months. The 15th Michigan saw continual action at Corinth, taking part in the siege and capture of the city in May, and its defense against Earl Van Dorn's all-out assault on October 3-4. Throughout the year the regiment spent in northern Mississippi, they were also regularly harassed by the very effective Confederate guerrilla cavalry, and they responded with equal violence and success against the citizenry that supported (and comprised) the guerrillas.
From at least the late spring of 1862, Anschütz was detailed as brigade cook, running the bake house and cooking for General John M. Oliver and the occasional illustrious visitor, including Generals Grant, Halleck, and Buell. Anschütz was well liked by the general and his staff, and was apparently an impressive cook who displayed an equal talent for impressing food and supplies from locals. He appreciated his comparatively soft position in the army, and was glad to be able to ride a horse, to have as much as he wanted to eat and not to have to carry a weapon. Yet his patriotism and willingness to accept personal sacrifice for the union cannot be questioned. Anschütz came to detest the southern people for waging their war of disunion, and he was of the strong opinion that they did not deserve mercy as a result. His gleeful stories of appropriating supplies from the homes of southerners and of seeing the women reduced to a state of helplessness are rooted in a hard edged, but deeply moral view of the conflict.
During the winter of 1862, the 15th Michigan were ordered to Grand Junction, Tennessee, to guard the railroad center against Confederate guerrillas. In the Spring, it appears that Anschütz fell seriously ill and was hospitalized for some time. His regiment, meanwhile, joined in the Vicksburg Campaign, and Anschütz was on his way to rejoin them in the trenches on the back side of Vicksburg in late June when he was last heard from. He was listed as having deserted from Grand Junction on May 20th, 1863, but on balance, it appears more likely that this report was mistaken, perhaps intentionally so. A dispute with Major Morris of his regiment may have resulted in Anschütz's legitimate medical leave being reported as desertion, with his untimely death preventing the error from being corrected.