The Battle of Island Number Ten was an engagement at the New Madrid or Kentucky Bend on the Mississippi River – forming the border between Missouri and Tennessee – during the American Civil War, lasting from February 28 to April 8, 1862. Island Number Ten, a small island at the (Tennessee) base of a tight double turn in the river, was held by the Confederates from the early days of the war. It was an excellent site to impede Union efforts to invade the South by the river, as ships had to approach the island bows on and then slow to make the turns. For the defenders, however, it had an innate weakness in that it depended on a single road for supplies and reinforcements. If an enemy force managed to cut that road, the garrison would be isolated and eventually be forced to surrender.

The Kentucky Bend, variously called the New Madrid Bend, Madrid Bend, Bessie Bend, or Bubbleland, is an exclave of Fulton County, Kentucky, encircled by the states of Tennessee and Missouri. It is a portion of a peninsula defined by an oxbow loop meander of the Mississippi River, and its inclusion in the state of Kentucky stems from uncertainties of the course of the Mississippi River when the boundary between Tennessee and Kentucky was established.