The Union was opposed by 11 southern slave states that formed the Confederate States, or the Confederacy. All of the Unions states provided soldiers for the U. S. Army, the Border states played a major role as a supply base for the Union invasion of the Confederacy. The Northeast provided the resources for a mechanized war producing large quantities of munitions and supplies. The Midwest provided soldiers, food, horses, financial support, Army hospitals were set up across the Union. Most states had Republican governors who energetically supported the war effort, the Democratic Party strongly supported the war in 1861 but in 1862 was split between the War Democrats and the anti-war element led by the Copperheads. The Democrats made major gains in 1862 in state elections. They lost ground in 1863, especially in Ohio, in 1864 the Republicans campaigned under the National Union Party banner, which attracted many War Democrats and soldiers and scored a landslide victory for Lincoln and his entire ticket. The war years were quite prosperous except where serious fighting and guerrilla warfare took place along the southern border, prosperity was stimulated by heavy government spending and the creation of an entirely new national banking system. The Union states invested a great deal of money and effort in organizing psychological and social support for soldiers wives, widows, orphans, and for the soldiers themselves. Most soldiers were volunteers, although after 1862 many volunteered to escape the draft, Draft resistance was notable in some larger cities, especially New York City with its massive anti-draft riots of 1863 and in some remote districts such as the coal mining areas of Pennsylvania. In the context of the American Civil War, the Union is sometimes referred to as the North, both then and now, as opposed to the Confederacy, which was the South. The Union never recognized the legitimacy of the Confederacys secession and maintained at all times that it remained entirely a part of the United States of America, in foreign affairs the Union was the only side recognized by all other nations, none of which officially recognized the Confederate government. The term Union occurs in the first governing document of the United States, the subsequent Constitution of 1787 was issued and ratified in the name not of the states, but of We the People of the United States, in Order to form a more perfect Union. Union, for the United States of America, is repeated in such clauses as the Admission to the Union clause in Article IV. Even before the war started, the preserve the Union was commonplace. Using the term Union to apply to the non-secessionist side carried a connotation of legitimacy as the continuation of the political entity. In comparison to the Confederacy, the Union had a large industrialized and urbanized area, additionally, the Union states had a manpower advantage of 5 to 2 at the start of the war. Year by year, the Confederacy shrank and lost control of increasing quantities of resources, meanwhile, the Union turned its growing potential advantage into a much stronger military force
Charleston Mercury Secession Broadside, 1860 - "The Union" had been a way to refer to the American Republic
The Union had large advantages in men and resources at the start of the war, and the ratio grew steadily in favor of the Union. In the chart, "cauc men" means white men (Caucasian).