On September 23, 1862, Lincoln issued a proclamation stating that on the first day of the new year he would declare free all slaves in any portion of the United States then in rebellion. On January 1, 1863, he issued the Emancipation Proclamation. This proclamation could be enforced only in those portions of the seceded states which were held by the Union armies. It did not free slaves in loyal states and did not abolish the institution of slavery anywhere. Slavery was abolished by the states of West Virginia, Missouri, and Maryland between 1862 and 1864. Finally, in 1865, it was abolished throughout the United States by the adoption of the Thirteenth Amendment.

Many persons in the North thought that the Southerners had a perfect right to secede if they wished. Some of these persons sympathized so strongly with the Southerners that they gave them important information and did all they could to prevent the success of the Union forces. It was hard to prove anything against these Southern sympathizers, but it was dangerous to leave them at liberty.

So Lincoln ordered many of them to be arrested and locked up. Now the Constitution provides that every citizen shall have a speedy trial. This is brought about by the issuing a writ of habeas corpus, compelling the jailer to bring his prisoner into court and show cause why he should not be set at liberty. Lincoln now suspended the operation of the writ of habeas corpus. This action angered many persons who were quite willing that the Southerners should be compelled to obey the law, but did not like to have their neighbors arrested and locked up without trial.

At the outset both armies were made up of volunteers; soon there were not enough volunteers. Both governments then drafted men for their armies; that is, they picked out by lot certain men and compelled them to become soldiers. The draft was bitterly resisted in some parts of the North, especially in New York City.