The New International Encyclopædia/Mississippi Sound
MISSISSIPPI SOUND. A lagoon-like strait, 8 to 14 miles wide, washing the coasts of Alabama and Mississippi from Mobile Bay to the entrance of Lake Borgne, a distance of about 90 miles (Map: Mississippi, H 10). It is formed and separated from the Gulf of Mexico by several long and narrow islands or sand bars, one of which is fortified. It is moderately deep, generally tranquil, and is navigated chiefly by the steamers and coasting vessels running between Mobile and New Orleans by way of Lake Pontchartrain.