Original sentence: Additionally, the Republicans made charges of treason against “Copperheads” a successful campaign issue.It was the measure of genius of President Lincoln  not only that he won his war but that he did so by drawing upon and synthesizing the strengths of anti-slavery, free soil, democracy, and nationalism
Edited sentence: Additionally, the Republicans made “Copperhead” treason a successful campaign issue.It was the measure of genius of President Lincoln not only that he won his war but that he did so by drawing upon and synthesizing the strengths of anti-slavery, free soil, democracy, and nationalism