It is one of four such towers built in the 1840s to protect Kingston's harbour and the entrance to the Rideau Canal.

Cathcart Tower on Cedar Island, Shoal Tower in the Confederation Basin, Fort Frederick on the grounds of the Royal Military College of Canada, and Murney Tower were part of the same strategic improvements.

Although 16 Martello towers were built in Canada, only 11 are still standing,[1] four of them in Kingston.

[3] The guns of Shoal Tower defended the approaches of Kingston Harbour.

A dispute between Great Britain and the United States over the boundary between British Columbia and Oregon that threatened to lead to war and to the invasion of Canada (see Oregon crisis) prompted their construction.