Short answers, pulled from the story.
Island Number Ten served as a critical defensive position for Confederate forces in 1862 due to its unique geography. The river made a tight double turn that forced Union ships to approach head-on and slow down, exposing them to shore batteries for over a mile. This location allowed Confederates to control river traffic while trapping their own garrison if supply lines were cut.
Maj. Gen. John Pope assumed command of the Union Army of the Mississippi on the 23rd of February 1862. He led an army numbering 10,000 men toward New Madrid and coordinated the siege operations against the island defenses. Pope worked alongside Flag Officer Foote to execute naval maneuvers including the famous gunboat runs past the batteries.
The siege officially began when gunboats and mortars arrived on the 15th of March 1862. Confederate forces surrendered after realizing their position was hopeless following events in late April 1862. The campaign concluded with the capture of thousands of soldiers who were subsequently transported to Madison, Wisconsin.
By mid-March 1862, five batteries containing 24 guns stood on the shore above the island. Another 19 guns were placed in five batteries directly on the island itself. A floating battery named New Orleans with nine guns was also moored at the west end of the island.
Commander Henry Walke ran his vessel the Carondelet through the Confederate fire zone on the 4th of April 1862 without being discovered until reaching Battery No. 2. This passage marked the introduction of a new tactic where steam power allowed ships to neutralize fixed defenses or bypass them entirely. This method later became commonplace during the Civil War at locations including Vicksburg and Mobile.