The American Civil War forever changed the course of naval warfare with the introduction of ironclad-protected steam-propelled warships and submarines, in addition to the newer and more powerful naval artilleries. Below are the 17 naval battles that played a significant role in the outcome of the overall Civil war off the ground and into the waters of the divided Americans.

#1 First Battle of Fort Sumter | April 12-13, 1861

At the break of dawn of April 12, 1861, a 10-inch mortar round was shot from Fort Johnson and into Fort Sumter, and like the straw that broke the camel’s back, that single shot marked the beginning of one of the bloodiest wars in American history.

The shot was fired by Lt. Henry S. Farley under the command of Captain George S. James. The senior officer initially offered the first shot to a notable Virginian secessionist, Roger Pryor, but he declined, saying that he could not fire the first gun of the war. After nearly 36 hours of fighting, with low ammunition and men hungry and exhausted, Union commander Robert Anderson agreed to a truce and surrendered their position to Confederate commander P. G. T. Beauregard’s men. Giving the first victory to the Confederacy. Little did they know, however, that the fight was far from over. In fact, they will be in it for the next four years.

#2 Battle of Gloucester Point | May 7, 1861

Days following the surrender of Fort Sumter to the Confederate Army, tens of thousands of Union drafted men were dispatched to stifle the spread of the uprising. President Abraham Lincoln ordered to include Virginia in the Union blockade, so the Confederates immediately built fortifications to deny the Union access to local estuaries. Upon hearing this, the USS Yankee, under the command of Lt. Thomas O. Selfridge Jr., was assigned to scout the said defensive wall at Gloucester Point opposite Yorktown on May 7, 1861. As soon as the Confederates spotted the steam tugboat, cannon fire exchange commenced.

#3 Battle of Aquia Creek | May 29-June 1, 1861

Union Navy gunboats and Confederates shore batteries went head-to-head on the Potomac River on the 29th at the merging streams of the Aquia Creek in Stafford County, Virginia. Unlike the earlier naval action, the Battle of Aquia Creek lasted about 72 hours, the longest thus far. The exchange of cannon fire was a continuation of the Confederates’ efforts to block the Union forces from moving further into the Potomac River, inflicting little-to-no damage or severe casualties for each side. The Confederates fired the first boiler-torpedo weeks following that battle with the support of mines placed around the Aquia Creek, equipped with gunpowders enough to blow up a ship the size of the slop-of-war Pawnee.

#4 Battle of Hatteras Inlet Batteries | August 28-29, 1861

The first combined operation involved Union Army troops and Navy sailors launching an attack on the Confederates’ fortified Hatteras Inlet. It was North Carolina’s busiest port and a vital supply line for Virginia’s secessionists. With little defense and artillery unable to retaliate against the bombarding fleet, Union forces landed on shore and overran both Confederate-guarded forts, Fort Clark and Fort Hatteras. This battle was the first time the naval blockading strategy was used.

#5 Battle of the Head of Passes | October 12, 1861

Six months into the war, the Confederacy launched a naval raid employing its river defense “mosquito fleet” against the Union blockade squadron moored at the Head of Passes. This was the first time the secessionists used the ironclad ram CSS Manassas in combat, supported by three fire rafts chained together. Hours passed, and the Confederates withdrew from the battle because supplies ran low.

Meanwhile, the Union fleet found themselves on a “comic opera” when the Captain of the supporting vessel Vincennes misread a signal and ordered his men to abandon the ship in panic. Upon reaching the flagship USS Richmond and the anticipated explosion didn’t occur aboard Vincennes, a fuming Captain John Pope ordered the humiliated Captain to go back. The battle concluded with no casualties, thus dubbed the “bloodless naval battle of the American Civil War.”

#6 The Battle of Port Royal | November 7, 1861

The Battle of Port Royal was the first major naval battle and one of the earliest amphibious operations of the American Civil War. The Union forces planned a combined army-navy campaign to seize the Port Royal Sound in South Carolina from the hands of the Confederacy. Once taken, the Union Navy intends to establish a coaling station for their steam fleet and provide troops with a base of operation. For this to work, the Navy was tasked to engage the two Confederate forts as a diversion while the Army land on shore to take care of the rest of the rebels on the ground. Unfortunately, bad weather put the plan on skew omitting the infantry landing altogether, leaving the battle up to the Navy to take on the fortifications of what its Blockade Board calls the “finest harbor south of Chesapeake Bay.”

Tactics were adjusted, and the new strategy resulted in a four-and-a-half-hour gun battle that took a heavy toll on the Union’s fleet and the Confederate garrison. The defenders retreated in the afternoon, leaving its most important seaports in the Union’s hands.

#7 Battle of Lucas Bend | January 11, 1862

While this naval engagement might be small compared to its counterparts, this was the first battle that the Union Navy used ironclad warships steaming on the Mississippi River en route to the Confederates’ position in Tennessee. The action resulted in a significant change in warships, demonstrating for the first time the effectiveness of the ironclad while permanently ditching the timber-clad (the predecessor of the ironclad that the Unions used as warship armors) out of naval warfare.

#8 Battle of Hampton Roads | March 8-9, 1862

Building an ironclad warship of their own, the CSS Virginia went for the USS Monitor the morning after sinking several Union fleets the day before (March 8). The two ironclads exchanged fire, but each shot would just glance off the iron armor causing little-to-no damage. Finally, in frustration, Virginia tried to ram the smaller Monitor but was unsuccessful. Several hours passed, and both warships withdrew, resulting in a tactical draw. Also dubbed the Battle of Ironclads, this was the first naval battle that two such warships faced off, and though it was a draw, its impact will result in a shift in future combat.

#9 Battle of Island Number Ten | February 28-April 8, 1862

Just four days before the marking of the first year of the American Civil War, the Confederacy had its first defeat on the Mississippi River. The territory they lost? A small island called Island Number Ten that the successionists had captured earlier in the war. For a while, the site was perfect for slowing Union efforts from entering the South side of the river. However, as the Union severed its supply line again, forces on the isolated island eventually ran out of food and ammunition, forcing the Confederates to surrender.

#10 Battle of Plum Point Bend | May 10, 1862

After taking an L weeks earlier, the Confederates finally had their retribution when its surprise attack, done by the Confederate River Defense Fleet, turned out to be a success that took place at Plum Point Bend on the Mississippi River. The raid sank two Union warships after getting rammed by the former’s fleet. The wrecked warships, however, were hoisted and repaired later and recommissioned back to service.

#11 Battle of Fort Hindman | January 9-11, 1863

The fighting between divided America continued to intensify as it approached Year 2. So far, the Union forces have successfully steamed towards the mouth of the Arkansas River, where they met the Confederate garrisons at Fort Hindman, also known as the Arkansas Post. The outcome of this battle would be critical, as the Arkansas Post would allow Union forces to advance deeper into the vast waterways while also serving as an assembly point.

The Union won the battle on the 11th, with the largest surrendering Confederates west of the Mississippi River, at least until the war’s end, thanks to the well-coordinated execution of the combined arms strategy.

#12 Second Battle of Sabine Pass | September 8, 1863

The Second Battle of Sabine Pass was a failed Union Army attempt to invade the Confederate State of Texas; despite its Navy’s assistance, it lost at least three gunboats in combat. Nevertheless, it was known as the war’s most one-sided Confederate victory and was recognized by Confederate President Jefferson Davis as “the most remarkable in military history.” French Mexico joined the fighting to assist the Confederate Army, but the two never joined forces after the Confederacy won.

#13 Attack on USS New Ironsides | October 5, 1863

With its commerce and warfare routes at stake, the Confederacy launched one of its secret weapons, the CSS David, and struck the unassuming USS New Ironsides deep into the night of October 5 with a spar torpedo. New Ironsides, known as the most formidable warship of the Union Navy, survived the explosion and immediately countered the attack, severely damaging David. It was bad that its Captain ordered the crew to abandon the ship.

#14 Battle of Mobile Bay | August 2, 1864

Three fortresses, protected by a small yet capable fleet and an extensive underwater minefield—Mobile Bay was the most heavily guarded Confederacy port and successfully defended it until Union Navy commander David G. Farragut and his fleet finally secured the last standing bay. However, it wasn’t an easy feat. It took the Union forces several hours of intense fighting—enduring casualties and sinking ships because of the scattered torpedoes—before the badly beaten CSS Tennessee and its crew surrendered.

#15 Second Battle of Fort Fisher | January 13-15, 1865

Often referred “Gibraltar of the South,” this battle was the last major fighting on the Confederate coastal stronghold and the largest amphibious assault of the Union forces involving men from the Army, Navy, and Marine Corps. If Fort Fisher were to be taken down, the last standing seaport of the Confederacy, the Wilmington in North Carolina, would also crumble. Hence, the Confederate garrison fought tooth and nail, ensuing in a grueling battle against a large number of Union forces.

After two days of fighting and over two thousand casualties from each side, Fort Fisher fell off from the Confederacy and into the Union’s hands, and from then on, the Rebel’s days were numbered.

#16 Battle of Trent’s Reach | January 23-25, 1865

Following its major victory at Fort Fisher, the Union Navy steered its ships and defended its blockade along Virginia’s James River against desperate Confederate warships attempting to break through and attack City Point—where General Ulysses Grant’s base was located, and most of its supplies were stored. Grant was besieging the trenches against Robert E. Lee in Petersburg, and the latter’s warships were supposed to aid the intense fighting on land by cutting Grant’s supply line, but the Confederate Navy failed and withdrew, leaving Lee to continue his clearly tilted battle in Petersburg.

#17 The Surrender of the CSS Shenandoah | November 6, 1865

Unaware that the war had ended months ago, the CSS Shenandoah steamed around until a British trader relayed the state of affairs. Shenandoah has been sailing around for more than 12 months with the task of disrupting the Union’s economy by raiding passing trading ships. Upon hearing the news, the commander of the commerce raider vessel was reluctant to land in the United States for fear of facing piracy charges, so he surrendered to the British government instead.

Shenandoah was the last sovereign Confederate flag to be officially furled and the last known to have fired the final shot of the Civil War.