When the Civil War began, the foremost issue on the mind of the average person questioned whether or not states had the right to secede from the Union. Secessionists believed that each state was autonomous, not unlike the countries which belong to the modern-day European Union. As such, secessionists claimed that each state had every right to leave the Union. Supporters of the Union cause believed that secession was treason, and that any state government refusing to acknowledge the authority of the federal government was in rebellion against the country.