This is the latest in a series of occasional articles on the shared histories of Bermuda and the United States, which celebrates the 250th anniversary of its independence this year. The articles, by Heritage Matters author Edward Harris, will run throughout the year.

As had been the case since settlement in 1612, the northern flanks of the Bermuda archipelago were protected by the defences of the North Lagoon and the extensive reefs.

The latter were conveniently arranged by Mother Nature in a great arc of treacherous rock from Chubb Heads in the west, through the eponymous North Rock, to Mills Breaker in the east.

Thus the only early forts on that side were at Ferry Reach and Daniel’s Island, with a perhaps utterly useless work on Maria Hill on Ireland Island. Not a fort to be seen on the north coast of the our “Midlands”, which are centred upon Devonshire Parish.

As Mum brought her natural defences close the south side of the coast, there were from the earliest decades a number of small fortlets, or batteries, strung like a necklace of thorns on the sea front from Castle Harbour to Wreck Hill, some 22 in all.

Most of these were never upgraded, but amazingly a few survived into recent times. They well served their purpose of preventing the enemy from landing on the south shore beaches and marching inland in a coup de main to seize Bermuda. These works survived alteration after the American War of Independence, when Major Andrew Durnford renovated and added to forts at Castle Island and St George’s.

The kicker for Bermuda and the British came with the American Civil War on the one hand and major advances in military ordnance on the other. The increasing military might of the United States was exhibited by the war, and the development of coal-driven steam-shipping by the British was changing the strategic dynamics of power in the western North Atlantic. To paraphrase one British officer, it was necessary to “find a bit to put in the mouth of the horse”, the steed to be controlled being the United States.

On the other hand, munitions were changing, as steam and iron ships required heavier artillery than the strikes of five-centuries-old cannon balls. Projectiles, or elongated “shell” were invented and cannon changed to guns, eventually more efficiently loaded from the breech or rear, as opposed to the stuffing of the mouth of the ancient weapons. The new guns and shells then ushered in a new age of fortifications, as exhibited in our extraordinary Fort Cunningham.

All these changes were coalescing, fusing together if you will, during the Civil War, much to the benefit of the Bermuda economy, which had hit a bit of a reef at the end of that conflict, which freed slaves in the United States. Money poured into the island to effect the transition to the new ways of gunnery and the physical defence of the coast.

There were three sections to the change in forts and guns: the eastern at the vital St George’s Parish and the defence of the ‘Narrows”, the only ship channel to the Dockyard and the capital at Hamilton; the central, or “Midlands” in Devonshire, and in the west from Whale Bay to Ireland Island. We make some comments today on the happenings in the Midlands.

While some land had apparently already been acquired for the British Army camp at Prospect Hill, for the new works, large swathes of properties were appropriated for the three major forts of the Prospect Position, from Fort Hamilton in the west to the central Fort Prospect to the easterly Fort Langton (destroyed in the 1980s for a bus depot).

Their purpose was to remove or delay an invading American Army marching overland from the beaches of the south coast to Spanish Point from where they could bombard the Dockyard at will. Several small positions were also established for horse-drawn mobile batteries on the coast, as survives on the grounds of the Coral Beach Club.

Like Fort Cunningham, the forts were made in the “polygonal trace” surrounded by ditches, as exhibited in the very deep and splendidly maintained one at Fort Hamilton. Fort Prospect, to complete the inventory, was slathered over with whitewash to form a water catchment for tanks inserted into its ditch, the fresh aqua to supply the City of Hamilton.

The three forts were all armed with the fancy new “Moncrieff Disappearing Carriage”, one of which was restored some years ago under the superb supervision of Andrew Pettit, then government officer in charge of some of Bermuda forts.

For its 64-pounder gun and setting, it is a unique surviving example of that weapon of the period. At Fort Langton, such guns fired into the wilds of Devonshire, Smith’s and Paget Parish to the east and south, while larger fixed Rifled Muzzle Loader coastal guns protected the South Channel to the Dockyard.

All in all, in the Midlands in that new period of military works some suffered much loss of their ancestral lands, while yet again, Bermuda generally did well in the 20 years after the Civil War, thanks to having a potentially hostile neighbour to the west. “A people unable, or unwilling, to restrain among its people a tendency to violence”, opined another British officer!

• Dr Edward Harris is the founding executive director emeritus of the National Museum of Bermuda