Mississippi River in the American Civil War

"[1] In April 1862, the Union secured two key points, New Orleans at the mouth of the river and a double-bend on the Kentucky-Tennessee line, leaving only the middle section in Confederate hands.

When the major river-ports of Memphis and Vicksburg fell (followed automatically by Port Hudson), the liberation of the Mississippi was complete, and Abraham Lincoln declared "The Father of Waters again goes unvexed to the sea.

"[2] This split the Confederacy in two, with the western half forced to operate as a separate department, the Trans-Mississippi Theater, greatly inhibiting supplies and communications, and tilting the odds decisively in favor of the Union.

Union Major-General John Pope arrived unexpectedly, before winter was over, easily took New Madrid, and then ordered two gunboats to run the island batteries, covering his crossing to the east (Tennessee) bank, whereupon the outnumbered enemy surrendered.

When the boom was broken by gunboats, the fleet forced its way in, opposed by ironclads and fire-rafts, eventually enabling the infantry to occupy the city and set up a Union government for the rest of the war.

A force under Maj. Gen. John C. Breckinridge attacked at dawn, killing Union commander Thomas Williams, and driving his men into defensive lines, protected by their gunboats.

His orders were to capture Port Hudson, the only other remaining Confederate stronghold on the river, but his assault failed, and he settled into a siege - at 48 days, the longest in American history up till then.