In the 18th century and most of the 19th, a sloop-of-war in the Royal Navy was a warship with a single gun deck that carried up to eighteen guns.
 The rating system covered all vessels with 20 guns and above; thus, the term "sloop-of-war" encompassed all the unrated combat vessels, including the very small gun-brigs and cutters.
 In technical terms, even the more specialised bomb vessels and fireships were classed as sloops-of-war, and in practice these were employed in the sloop role when not carrying out their specialized functions.
HMS "Hecla" was a Royal Navy "Hecla"-class bomb vessel launched in 1815.
 Like many other bomb vessels, was named for a volcano, in this case Hekla in Iceland.
 She served at the Bombardment of Algiers.
 Subsequently she took part in three expeditions to the Arctic.
 She then served as a survey vessel on the coast of West Africa until she was sold in 1831.
Fort Morgan is a historic masonry Pentagonal bastion fort at the mouth of Mobile Bay, Alabama, United States.
 Named for Revolutionary War hero Daniel Morgan, it was built on the site of the earlier Fort Bowyer, an earthen and stockade type fortification involved in the final land battles of the War of 1812.
 Construction was completed in 1834 and it received its first garrison in March of the same year.
Fort McHenry, in Baltimore, Maryland, is a historical American coastal pentagonal bastion fort best known for its role in the War of 1812, when it successfully defended Baltimore Harbor from an attack by the British navy from the Chesapeake Bay September 13–14, 1814.
 It was first built in 1798 and was used continuously by U.S. armed forces through World War I and by the Coast Guard in World War II.
 It was designated a national park in 1925, and in 1939 was redesignated a "National Monument and Historic Shrine".
HMS "Aetna" was one of the Royal Navy bomb vessels involved in the attack on Fort McHenry in the Battle of Baltimore and the bombardment of Fort Washington, Maryland in 1814, during the War of 1812.
 In these actions she was commanded by Richard Kenah.
 Prior to this, "Aetna" participated in the second Battle of Copenhagen in 1807 and the Battle of the Basque Roads in 1809.
 In both these actions, she was commanded by William Godfrey.
Bomb vessels served in the Royal Navy over a period of about 150 years.
 The concept entered the Navy in the 1680s, based on French designs and usage, and remained in service until the mid-19th century.
 Bomb vessels were designed to bombard enemy positions on land, such as towns and fortresses.
 For this they were fitted with one or two mortars that could fire high-trajectory shells over considerable distances.
 They were fleet support units, and as such were not intended to engage enemy ships directly except in self-defence, and so received only light conventional armament.
 They could also carry explosive shells in addition to regular shot, and were the only ships in the navy so equipped.
 The first designs tended to be ketch-rigged, to allow the mortars to fire forward.
 Though effective, this arrangement made for poor sailing qualities and by 1790 the ship rig had replaced the ketch.
The raid on Boulogne in 1801 was a failed attempt by elements of the Royal Navy led by Vice Admiral Lord Horatio Nelson to destroy a flotilla of French vessels anchored in the port of Boulogne, a fleet which was thought to be used for the invasion of England, during the French Revolutionary Wars.
 At dawn on 4 August, Nelson ordered five bomb vessels to move forward and open fire against the French line.
 Despite the inferior gunpowder of French artillery and the high number of shots fired by the bomb vessels, the British sustained more casualties and withdrew.
 The night of 16 August Nelson returned and tried to bring off the flotilla, attacking with seventy boats and nearly two thousand men organized into four divisions, but the attack was successfully repelled by the defenders, led by Admiral Latouche Tréville.
HMS "Wilhelmina" was a 32-gun fifth rate frigate of the Royal Navy.
 She was previously a Dutch ship and had been built in 1787 for the Dutch Republic as the "Wilhelmina".
 She was renamed "Furie" in 1795, after the establishment of the Batavian Republic as a client state of the First French Empire.
 Like other Dutch ships at that time, she was pressed into service as part of French plans to support the Irish Rebellion of 1798 in the hope of destabilising Britain.
 The British captured her and the Dutch corvette "Waakzaamheid" in 1798 while the two were supporting French and Irish forces involved in the Irish Rebellion.
 The Royal Navy took both into service, with "Furie" regaining her original name.
 Sailing as HMS "Wilhelmina", she spent the bulk of her later career in the East Indies, serving mostly as a troopship.
 Here she fought an unequal battle against a large French privateer, and succeeded in driving her off and protecting a merchant she was escorting.
 "Wilhelmina" was almost the ship that faced a superior French squadron at the Battle of Vizagapatam, but she was replaced beforehand by the larger HMS "Centurion" .
 She spent the rest of her days as a guardship in Penang, and was sold there in 1813.
HMS "Infernal" was an 8-gun bomb vessel of the Royal Navy, constructed in 1757 and in service until 1763.
 Designed by Thomas Slade, she was the prototype for six subsequent Infernal class bomb vessels which saw service in the Mediterranean and the West Indies during the Seven Years' War with France.
 In 1760 she was refitted as a sloop and returned to active service in the Caribbean.
Antwerp Citadel (Spanish: "Castillo de Amberes" , Dutch: "Kasteel van Antwerpen" ) was a pentagonal bastion fort built to defend and dominate the city of Antwerp in the early stages of the Dutch Revolt.
 It has been described as "doubtlesse the most matchlesse piece of modern Fortification in the World" and as "one of the most studied urban installations of the sixteenth century".

Question: HMS Aetna was one of the Royal Navy bomb vessels that were involved in the attack on what historical American coastal pentagonal bastion fort, that was first built in 1798?
Answer: Fort McHenry