>>513255692
>The most popular union army song were about literally dying for niggers.
Abraham Lincoln's favorite song was literally Dixieland, retard.

As for the song that was supposedly popular in the Union Army? The only one I can think of that has lyrics that even remotely resemble what you described is the Battle Hymn of the Republic. But it was not a popular song anywhere until long after the Civil War. The specific lyric is, "As He died to make men holy, let us die to make men free".