President Obama has Seal Team Six. President Lincoln had William Cushing. Although Cushing was expelled from the Naval Academy, he talked his way into a commission in the U.S. Navy during the Civil War. He was soon promoted to lieutenant.
In all navies, the higher your rank, the bigger the ship you command. Commanders command small ships and captains bigger ships. Admirals sit around planning how to crush the enemy by buying massive fleets and advanced weapons.
Cushing apparently reasoned something along the lines of “Hey I am just a lieutenant. Nobody is going to give me a ship. So what can I do with a small boat and several dozen men?” Time after time, he managed to confound the elaborate planning of admirals on both sides.
Although the battle between the USS Monitor and the CSS Merrimac is much more famous, Cushing and a few dozen sailors sank another powerful Confederate ironclad in 1864. The CSS Albermarle had managed to chase the U.S. Navy away from North Carolina.
Cushing snuck up to the Albermarle’s dock in a small boat. He attached explosives. The huge hole in her hull put the Albermarle out of action for the rest of the war, confounding both Union and Confederate admirals who thought the Union didn’t have a ship powerful enough to sink her.
Cushing helped capture several Confederate forts by sneaking up on the backside while the rest of the Union forces were besieging the front. He captured Fort Anderson in North Carolina by scaring the Confederates out of it. He built an imitation monitor-type gunboat out of wood. After seeing the fake ironclad steam by the fort, the Confederate soldiers promptly fled.
One time, just for fun, he snuck into a small town and kidnapped a breakfasting Confederate general. It was reported that by the end of the war, the mere mention of his name would cause Confederates to flee.
To find out more about this fascinating hero, see Commander Will Cushing and Lincoln's Commando. He is also mentioned at length in Admiral David Porter’s Naval History of the Civil War. Typical of the way he was viewed by admirals, Porter is both admiring of and frustrated by Cushing. Many of Cushing's original dispatches are reprinted in the 137-volume War of the Rebellion: A Compilation of the Official Records of the Union and Confederate Armies, available in Government Publications and Special Collections and Making of America digital collection. The shorter Civil War Naval Chronology, 1861-1865 mentions him often.