Brig. Gen. John P. McCown, decided to evacuate the town after only one day of heavy bombardment, moving most of his troops to Island No. 10, abandoning his heavy artillery and most of his supplies. Gantt's Brigade now included the 11th and 12 Arkansas Infantry Regiments, the 4th Arkansas Infantry Battalion, may of whom were manning guns on Island No. 10. and the 55th Tennessee Infantry Regiment. Two days after the fall of New Madrid, Union gunboats and mortar rafts sailed downstream to attack Island Number Ten. Over the next three weeks, the island's defenders and forces in the nearby supporting batteries were subjected to a steady bombardment by the flotilla, mostly carried out by the mortars. At the same time, the Union forces at New Madrid were digging a canal across the neck of land east of the town to bypass Island No. 10. Several transports were sent to the Army of the Mississippi when the canal was finished, which provided the army with a way to cross the river and attack the Confederate troops on the Tennessee side. Pope persuaded Flag Officer Andrew Hull Foote to send a gunboat past the batteries, to assist him in crossing the river by keeping off any Southern gunboats and suppressing Confederate artillery fire at the point of attack. The USS Carondelet, under Commander Henry Walke, slipped past the island on the night of April 4, 1862. This was followed by the USS Pittsburg, under Lieutenant Egbert Thompson two nights later. With the support of these two gunboats, Pope was able to move his army across the river and trap the Confederates opposite the island, who by now were trying to retreat. Outnumbered at least three to one, the Confederates realized their situation was hopeless and decided to surrender. The bulk of the 12th Arkansas was captured at Island Number Ten and sent to prisoner of war camps with the other captured regiments from that post. At the prison camps, they joined with those regiments previously captured at Ft Donelson. As was the case with other regiments, there were escapees from the surrender of Island Number Ten, including those in hospital or on detached duty, etc. The members of the 12th Arkansas who avoided capture at Island Number Ten were consolidated into two companies assigned on June 16, 1862, as second companies D and F of the 6th Arkansas Infantry Regiment. These