Even if you are not a football fan, you are probably aware of the Army-Navy game, in which the two military academies seek to prove their superiority on the gridiron. You may not realize, however, that the rivalry between Army and Navy goes back to a period before the Civil War.
Samuel F. DuPont joined the Navy before the Naval Academy was founded, and he worked his way up through the ranks. When Pres. Lincoln authorized a joint military expedition to the coast of South Carolina in 1861, he promoted DuPont to the rank of flag officer and put him in charge of the fleet of over 80 ships. We know much about that expedition because of the letters DuPont wrote to his wife. In them he was outspoken about his criticisms of the Army, although he phrased his harshest terms in his native French. The soldiers, he told her, were "the most helpless people I ever saw," and he insisted that they would be entirely useless during the invasion of the South Carolina coast.
DuPont was successful in his attack of Port Royal Sound and was given full credit for establishing the Union foothold on the Sea Islands, and making it possible for the Union to extend its control over the coast of Georgia and the northern coast of Florida. He was less successful, however, in waging a successful attack on Charleston Harbor. Time and again he aimed his ships at the heart of the Confederacy, and every time he failed. He blamed those results on the Army's inability to take out the fortifications that surrounded and guarded the city of Charleston.
General Thomas William Sherman (he of the most unfortunate hair-do in the history of the U.S. Army!) was a West Point graduate and some 10 years younger than DuPont. The two men had quite different personalities, but they shared a tendency to blame their failures on each other. We know much about Sherman from his official dispatches, in which he complained to Washington officials that his troops were poorly equipped for the task they had been assigned and that the Navy was hindering his every effort.
Note that this General Sherman is NOT the same man who led "Sherman's March to the Sea" at the end of the Civil War. T. W. Sherman was an experienced soldier, having participated in the Mexican-American War and during the Kansas troubles in the 1850s. He had even spent some time stationed at Fort Moultrie near Charleston, so he was quite familiar with the territory he was expected to control. He was replaced in South Carolina after only four months, while DuPont remained there until he was relieved of duty in July 1863.