What are all 19 free states during the Civil War in the US?

During the Civil War, the 19 free states were Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, Connecticut, New York, New Jersey, Pennsylvania, Ohio, Indiana, Illinois, Iowa, Wisconsin, Minnesota, California, Oregon, Kansas, and Michigan. These states did not permit slavery and were primarily located in the North and West. They played a crucial role in supporting the Union war effort against the Confederate states.