How Many States Were in the Union During the American Civil War?

By Staff WriterLast Updated Mar 31, 2020 4:07:54 PM ET
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During the American Civil War, there were 20 states in the Union, including Illinois, California, Indiana, Connecticut, Iowa, Michigan, Kansas, Maine, Massachusetts, New Jersey, Minnesota, New Hampshire, Vermont, New York, Oregon, Nevada, Pennsylvania, Ohio, Wisconsin and Rhode Island. The 11 states that seceded from the Union and formed the Confederate States of America were Louisiana, Arkansas, Texas, Mississippi, North Carolina, South Carolina, Virginia, Florida, Georgia, Alabama and Tennessee.