At the outbreak of the Civil War, Breckinridge quickly became an ardent supporter of the Union, not for its position against slavery, but for the sake of preserving the Union. He used his position as editor of the "Danville Quarterly Review" to advocate his position. He called for harsh measures against secession, and in time, accepted President Lincoln's immediate emancipation of slaves. He was chosen as the temporary chair of the 1864 Republican National Convention that re-nominated Lincoln for president, and his pro-Union speech was hailed by freshman Representative James G. Blaine as one of the most inspiring given at the event.