At first, the bustle of economic and military mobilization seemed to silence politics, but bipartisan unity did not last. Within a year, Democrats were labeling the Republican administration a “reign of terror” and denouncing as unconstitutional Republican policies expanding federal power, subsidizing private business, and emancipating the slaves. In turn, Republicans were calling Democrats the party of “Dixie, Davis, and the Devil.”

When the Republican-dominated Congress enacted the draft law in March 1863, Democrats had another grievance. The law required that all men between the ages of twenty and forty-five enroll and make themselves available for a lottery that would decide who went to war. It also allowed a draftee to hire a substitute or simply to pay a $300 fee and get out of his military obligation. As in the South, common folk could be heard chanting, “A rich man’s war and a poor man’s fight.”

Linking the draft and emancipation, Democrats argued that Republicans employed an unconstitutional means (the draft) to achieve an unconstitutional end (emancipation). In the summer of 1863, antidraft, antiblack mobs went on rampages in northern cities. In July in New York City, Democratic Irish workingmen—crowded into filthy tenements, gouged by inflation, enraged by the draft, and dead set against fighting to free blacks—erupted in four days of rioting. The New York City draft riots killed at least 105 people, most of them black.

Lincoln called Democratic opposition to the war “the fire in the rear” and believed that it was even more threatening to national survival than were Confederate armies. The antiwar wing of the Democratic Party, the Peace Democrats—whom some called “Copperheads,” after the poisonous snake—found their chief spokesman in Ohio congressman Clement Vallandigham. Vallandigham demanded: “Stop fighting. Make an armistice. . . . Withdraw your army from the seceding States.”

In September 1862, in an effort to stifle opposition to the war, Lincoln placed under military arrest any person who discouraged enlistments, resisted the draft, or engaged in “disloyal” practices. Before the war ended, his administration imprisoned nearly 14,000 individuals, most in the border states. The administration’s heavy-handed tactics suppressed free speech, but the campaign fell short of a reign of terror, for the majority of the prisoners were not northern Democratic opponents but Confederates, blockade runners, and citizens of foreign countries, and most of those arrested gained quick release. Still, the administration’s net captured Vallandigham, who was arrested, convicted of treason, and banished.