The Garrison's military purpose dates to at least the late 17th century, when it became the base and headquarters for the British West India Regiment in Barbados. Its central feature, the Garrison Savannah, served as a parade ground where troops drilled and reviewed, surrounded by barracks, officers' quarters, and administrative buildings constructed from the island's abundant coral limestone. Saint Ann's Fort anchored the western edge of the district, and it remains an active military installation today as the headquarters of the Barbados Defence Force. The buildings that survive tell the story of a garrison town in miniature: a clocktower-topped guardhouse built around 1803, a magazine, a sentry box, prison cells from the military justice system, and the building that now houses the Barbados Museum. Highway 7 bisects the district, a modern road slicing through centuries of military geometry.

In 1751, a 19-year-old Virginian named George Washington arrived in Barbados with his half-brother Lawrence, who was suffering from tuberculosis and hoping the tropical climate might ease his lungs. The brothers settled into a house in the Garrison's Bush Hill section for six weeks. During that stay, young George contracted smallpox, a miserable experience that nevertheless granted him immunity from the disease that would devastate armies during the American Revolution decades later. The restored property, known simply as George Washington House, still stands within the Garrison, the only house outside the continental United States where the first president is known to have stayed. In 1997, First Lady Hillary Clinton unveiled a plaque at the site during an official visit with President Bill Clinton, commemorating the connection between the two nations.

By the mid-18th century, wealthy Barbadians and regiment officers had discovered a secondary use for all that flat, open turf. Horse racing began at the Garrison Savannah, a tradition that transformed the military parade ground into the island's premier sporting venue. The racetrack endures today, its oval circuit tracing the perimeter of the old drilling field, hooves thundering over ground where soldiers once marched in formation. The juxtaposition is pure Barbados: a military space repurposed for pleasure, the discipline of empire giving way to the exuberance of island life. Race days draw crowds from across the island, and the surrounding historic buildings provide a backdrop that no purpose-built racecourse could replicate.

The Garrison produced more than soldiers. Major-General Richard Clement Moody, born here in 1813 while his father Thomas served with the Royal Engineers, would go on to become the founder and first Lieutenant-Governor of British Columbia, shaping a Canadian province from the other side of the world. His brother James Leith Moody and several siblings were also born at the Garrison. The collection of rare and historic English cannons displayed on the grounds offers another thread connecting this small Caribbean district to the wider British Empire. In 2011, UNESCO recognized that significance by inscribing Historic Bridgetown and its Garrison as a World Heritage Site, preserving the district's layered history of military power, colonial administration, and national independence for future generations.