A patriotic song advocating the causes of Unionism and abolitionism, it became so popular that composer H. L. Schreiner and lyricist W. H. Barnes adapted it for the Confederacy.

[2] The song was so popular that the music publisher had 14 printing presses going at one time and still could not keep up with demand.

Louis Moreau Gottschalk thought so highly of the song that in his diary he confided that he thought "it should be our national anthem" and used it as the basis for his 1863 concert paraphrase for solo piano "Le Cri de délivrance," opus 55, and dedicated it to Root, who was a personal friend.

[3] "Battle Cry of Freedom" proved popular among Union soldiers during the American Civil War.

According to Henry Stone, a Union war veteran recalling in the late 1880s, the song helped the morale of Union soldiers: A glee club came down from Chicago, bringing with them the new song, "We'll rally 'round the flag, boys", and it ran through the camp like wildfire.

I do not know whether Mr. Root knows what good work his song did for us there, but I hope so.According to historian Christian L. McWhirter, the song's success and popularity among the Union was due to its even-handed references to both abolitionism and unionism.

Thus, both groups of Unionists, those opposed to slavery and secession, could utilize the song without reservation: The ability of "The Battle Cry of Freedom" to bridge divisions over emancipation is not surprising.

Those looking for anti-slavery sentiments could find them, but these elements were not so pronounced as to offend those who were solely unionists.

Freedom had many meanings in the Civil War – for instance, freedom from Confederate political tyranny or the oft-perceived "slaveholders' conspiracy" – but, in the context of Root’s political beliefs and other activities, he clearly meant to suggest some degree of abolitionism.Oh we'll rally round the flag, boys, we'll rally once again,[6] Shouting the battle cry of freedom, And we'll rally from the hillside, we'll gather from the plain, Shouting the battle cry of freedom.

Oh we're springing to the call for three hundred thousand more,[a] Shouting the battle cry of freedom!

And we'll fill the vacant ranks with a million freemen more,[7][8][b] Shouting the battle cry of freedom.

We will welcome to our numbers the loyal, true and brave, Shouting the battle cry of freedom!

So we're springing to the call from the East and from the West, Shouting the battle cry of Freedom; And we'll hurl the rebel crew from the land we love the best, Shouting the battle cry of Freedom.

We will welcome to our number The loyal, true and brave, Shouting the battle-cry of Freedom.

We'll meet the Rebel host, boys, With fearless hearts and true, Shouting the battle-cry of Freedom ; And we'll show what Uncle Sam Has for loyal men to do, Shouting the battle-cry of Freedom.