"Oh we'll hang Jeff Davis from a sour apple tree" (and similar) is a variant of the American folk song "John Brown's Body" that was sung by the United States military, Unionist civilians, and freedmen during and after the American Civil War. The phrase and associated imagery became relevant to the post-war legal issues surrounding the potential prosecution of former Confederate politicians and officers; the lyric was sometimes referenced in political cartoons and artworks of the time, and in political debates continuing well into the post-Reconstruction era.
Jeff Davis and the sour apple tree appear in print as early as August 1861. In 1880, a U.S. Army veteran claimed credit for first singing the lyric in spring 1862 in Virginia, having taken inspiration from a prior song about a "sick monkey in a sour apple tree." In 1947 a survivor of American slavery named Perry Vaughn recalled, "I fought in Abe Lincoln's army and played the bass horn in the Army band. I can still remember, like it was yesterday, playing 'We'll Hang Jeff Davis on a Sour Apple Tree.'"
A less bloodthirsty and more obscene variant was "We'll feed Jeff Davis sour apples 'til he gets the diarhee."
Richard Wright's 1938 novella Big Boy Leaves Home references a white-supremacist variant: "We'll hang ever nigger t a sour apple tree."
Jefferson Davis, the first and only president of the Confederate States of America, died of natural causes in 1889.