Mississippi becomes the second state to secede from the Union before the outbreak of the American Civil War.

Mississippi is a state in the Southeastern and Deep South regions of the United States. It borders Tennessee to the north, Alabama to the east, the Gulf of Mexico to the south, Louisiana to the southwest, and Arkansas to the northwest. Mississippi's western boundary is largely defined by the Mississippi River, or its historical course. Mississippi is the 32nd largest by area and 35th-most populous of the 50 U.S. states and has the lowest per-capita income. Jackson is both the state's capital and largest city. Greater Jackson is the state's most populous metropolitan area, with a population of 591,978 in 2020. Other major cities include Gulfport, Southaven, Hattiesburg, Biloxi, Olive Branch, Tupelo, Meridian, and Greenville.

Mississippi was the second southern state to declare its secession from the United States, doing so on January 9, 1861. It joined with six other southern states to form the Confederacy on February 4, 1861. Mississippi's location along the lengthy Mississippi River made it strategically important to both the Union and the Confederacy; dozens of battles were fought in the state as armies repeatedly clashed near key towns and transportation nodes.

The Perpetual Union is a feature of the Articles of Confederation and Perpetual Union, which established the United States of America as a political entity and, under later constitutional law, means that U.S. states are not permitted to withdraw from the Union.

January 9 is the ninth day of the year in the Gregorian calendar; 356 days remain until the end of the year.