Island Number Ten was an island in the Mississippi River near Tiptonville, Tennessee and the site of a major eponymous battle in the American Civil War. In the mid-19th century the United States Government began to adopt a uniform numbering plan for islands in the Lower Mississippi River (that part of the river below its confluence with the Ohio River near Cairo, Illinois). This system assigned each major island a number, which increased in the downstream direction. The purpose of this system was to create a level of certainty in documents describing islands in the river as to exactly which island was meant. To a large extent, however, the system had an unintended, and at times almost reverse effect. The numbering system was based on the premise that the islands were relatively permanent,