When he wasn't on the firing line fighting the enemy, the common soldier spent much of his time waging war against another, far more insidious invader: the common louse. Sanitation in the camps was poor because of a lack of both time and knowledge, and lice, flies, and mosquitoes were everywhere.
In his book Soldiers Blue and Gray (Warner Books, 1988, p. 154), James I. Robertson, Jr., writes:According to an Illinois captain, General William T. Sherman became so concerned that the "graybacks" would bodily carry off his army that he ordered the ranks to halt so that every man could divest himself of the pests.
"Hunting graybacks" quickly became a daily and unconcealed morning chore for most soldiers. Another popular remedy was to boil clothes in water. Still another method was to hold shirts and trousers directly over a fire (which at least guaranteed them an intense smoky odor for days thereafter). Turning one's shirt inside out, a Billy Yank observed, at least forced the vermin to make "a day's march" before locating their victim again. James Phillips of the 92nd Illinois saw futility in all such labors. "I change shirts and boil the gray backs pretty well which is death to most of them but there is jenerly enough kept for seed somewhere in the co[mpany]." Virginia infantryman Ted Barclay was appalled at the lice he discovered on himself. To his sister he confessed: "This evening I caught between 50 and 100 on my shirt and drawers. Excuse plain speaking but it is certainly not an exaggerated state of affairs."
As he usually did when confronted with an unfortunate situation that he could not change, the soldier made light of it, in this case turning it into an amusing song that might, with any luck, keep his mind off his unwanted visitors at least for the duration of its singing.
Many thanks to Dave Smith of Ironclad Publishing for giving me the book in which this song was found: The Singing Sixties: The Spirit of Civil War Days Drawn from the Music of the Times by Willard A. and Porter W. Heaps (University of Oklahoma Press, 1960, p. 153).
"The Graybacks So Tenderly Clinging"