Slave states: Delaware, Maryland, Virginia, North Carolina, South Carolina, Kentucky, Tennessee, Georgia, Florida, Alabama, Mississippi, Louisiana, Arkansas, Missouri, Texas
Free States: Maine, New Hampshire, Vermont, Connecticut, Rhode Island, New Jersey, New York, Massachusetts, Pennsylvania, Ohio, Indiana, Michigan, Illinois, Wisconsin, Minnesota, Iowa, California, Oregon
Almost all of these states were decided based on the Missouri Compromise creating a clear line of North v. South.