In the decade and a half after the Civil War, the American public school rose and fell as a central issue in national and state politics. After a relative calm on matters of education during and immediately after the War, the Republican Party and Catholic Church leaders in the late 1860s and early 1870s joined a bitter battle of words over the future of public education--who should control it, how should it be financed, and what should it teach about religion. These battles often reflected very different world views. Leading Protestant ministers and Republican politicians waved the threat of a rising antidemocratic "Catholic menace" as the new bloody shirt and championed their own educational ideal as a remedy--religiously neutral, ethnically and racially inclusive common schools. While Democrats tended to downplay school issues, Catholic Church leaders countered with their own screed: common schools were hardly common, embodying either inherently Protestant notions of religion or the atheism of no true religious creed at all. New York City became the epicenter of these cataclysmic debates, and the brilliant cartoonist Thomas Nast immortalized the Radical Republican side of the issue in the pages of Harper's Weekly. This essay focuses on the works of Nast and his popularity that makes him worthy of study; not only because his drawings offer a window into his own times, but because historians continue to turn to Nast's art as a kind of shorthand for the politics of public education in the 1870s. The most effective historical uses of Nast's work are those that link it to Republican Party rhetoric, particularly that of "Radical" Republicans. (Contains 12 figures.)