While aboard, Midshipmen were required to continue their education, studying mathematics and schooled in the ways of navigation, weapons, along with knot-tying classes, where more than fifty knots, splices, and hitches had to be mastered.

In a June 15 letter to his father, he expressed his regrets that he could not visit with family, who were only 30 miles away D.C.[14] Phelps served aboard the Bonita and Jamestown during the Mexican–American War, giving naval support to Winfield Scott's Army during the Siege of Veracruz.

In little time Phelps had already developed strong opinions about how the war should be conducted, and was displeased that the Navy was lending much of their service protecting merchant ships while sailors were coming down with scurvy for want of provisions.

[15] In 1857, after ten years of shore duty, Phelps was assigned to the USS Susquehanna, a side-wheel man-of-war and returned to serving at sea in the Mediterranean Squadron.

On October 11, 1861, Phelps, aboard the Conestoga, ascended the Tennessee River, and as the vessel approached Fort Henry the Confederates fired signal rockets into the sky, warning of its arrival.

Phelps' three timberclad gunboats were vulnerable to cannon fire and took up positions some distance behind Foote's ironclads for protection and began their bombardment of Fort Henry from long range.

[44] During the aftermath of the capture of Fort Henry, Phelps continued upriver to a landing at Cerro Gordo where the Confederates were in the process of building and completing an ironclad gunboat, Eastport.

Phelps proceeded to pursue fleeing Confederate transports with his other two gunboats, Conestoga and Lexington, while also engaging in a search and destroy mission, and creating havoc at every opportunity along the way.

[47][48] After five hours the faster Conestoga left the Lexington behind and closed in on Confederate Captain Sam Orr, who was forced to set his vessel, containing guns and ammunition, on fire.

Phelps' three timberclads finally arrived at Cerro Gordo by 7 p.m., eight miles downstream from Savannah, Tennessee, where it was greeted by Confederate small arms gunfire from the shores.

Alarmed, Grumpus stopped its engines and struck its colors, but her commander then quickly changed his mind, turned about and headed downriver, with Benton firing shells that fell short of her stern.

[61] General Pope advanced on New Madrid, an engagement that lasted from February 28 to March 14, with very few casualties,[62] and proceeded on to Point Pleasant, Missouri and using his guns to established a blockade of the river.

[66][67] After days of bombardment from Union gunboats and floating batteries, Pope was finally able to move his army across the river and trap the Confederates opposite the island, who by now were in retreat.

As Foote and Phelps were looking on from the Benton, a Confederate steamer DeSoto approached with a flag of truce with lieutenants George S. Martin and E. S. McDowell aboard with a message.

Foote forwarded their recommendation to Secretary of the Navy, Gideon Welles with the request that temporary command be given to Captain Charles Davis, as Acting Flag Officer.

The mortar boat opened fire at 5 a.m. By 6 a.m. eight Confederate rams rapidly steamed upriver, coming around Graighead Point, with black smoke revealing the advancing fleet in the distance.

Meanwhile, the remainder of the union fleet stretched back for ten miles and slowly made their way, reaching a group of small islands just north of Memphis.

The USS Queen of the West, then quickly steamed forward between the slow-moving ironclads and initiated the battle by ramming the CSS Colonel Lovell, almost cutting the vessel in two.

[91] By 7:30 a.m., the entire Confederate Defense Fleet had been destroyed, as the converted steamboats proved no match for the powerful Federal ironclads and rams, resulting in the immediate surrender of the city of Memphis to Union forces within a few hours.

[95] In August 1862 an expedition was sent down the river composed of the Benton, Mound City, and Bragg, together with four of Ellet's rams, the Switzerland, Monarch, Samson, and Lioness, all under the command of Phelps, with a detachment of troops under Colonel Charles R. Woods.

Writing to Whittlesey a week later, Phelps observed that "The vessels of this lower fleet are very beautiful as contrasted with our strange looking rivercraft; yet not one of them would have floated five minutes in the fire concentrated on four of our queer crafts at (Fort) Donelson".

[100] Phelps was not particularly fond of Farragut, describing him as a rash and impulsive man who felt that he must always keep busy for fear of being accused of "doing nothing", and who often "acts without purpose or a plan" based or common sense.

Porter didn't like the idea of taking his fleet past Alexandria but acquiesced and assigned the most formidable ships of the Mississippi Squadron to meet the task, which included the huge Eastport, commanded by Seth Phelps.

[107] Union Generals Nathaniel Banks and A. J. Smith, along with gunboat squadrons under the command of Admiral Porter were to meet at Alexandria, on March 17 and make their way up the Red River some 350 miles to Shreveport.

[109][110] During most of the year the river was navigable only by small, shallow draft, vessels, making Porter very reluctant to take his squadron past Alexandria, however, Banks persuaded him by pointing out that if the expedition to Shreveport failed, blame would fall on him.

Phelps already wanted to get there as soon as possible and sent the faster Fort Hindman and Cricket on ahead, arriving March 15, at the same time Confederate steamers were escaping upriver beyond the falls.

When Porter arrived from Alexandria he found that the Eastport had gotten past the shoals at Grand Ecore but could proceed no further due to the low river level which was rising very slowly.

When attacked by General Richard Taylor,[v] resulting in the Battle of Mansfield, Banks, suffering heavy losses, was forced to retreat to Pleasant Hill fifteen miles to the southeast.

Phelps lit the match himself, and both men barely made it off the vessel on to the awaiting Hindman in time before the Eastport exploded into pieces, with large sections of the hull falling all around them.

[124][127][128] In 1877 Phelps hired an architect, Thomas Plowman, and builder, Joseph Williams, to construct his retirement mansion located at 1500 13th Street, (also known as Logan Circle) at a cost of 5,500.