Citation

Swam the bayou under fire of the enemy and captured and brought off a boat by means of which the command crossed and routed the enemy.

http://www.cmohs.org/recipient-detail/208/cadwell-luman-l.php

http://www.iowahistory.org/museum/exhibits/medal-of-honor/cadwell-luman_cw/index.htm

On September 20, 1864 a detachment of the 2nd New York Cavalry, dismounted, approached a Confederate camp on an island in the middle of Alabama Bayou, near New Orleans. Sgt. Cadwell and another soldier swam across the 150 foot waterway to bring a small boat to their command. The boat allowed the unit to cross and capture the rebel camp, destroying its supplies and buildings, including an artillery piece.