Americans began to fortify San Juan Island even before the Joint Occupation Agreement of 1859. Anticipating war with Britain, they chose the site of Camp San Juan accordingly. Set on a high exposed hill overlooking Griffin Bay and the Strait of Juan de Fuca, the Americans moved quickly to build a military redoubt, an earthen defense against naval assault.
Robert’s Redoubt, named for Second Lieutenant Henry Martyn Robert, was to be 425 feet long and no less than 8 feet deep. Construction began in late August 1859 when Robert and his crew arrived at American Camp. At completion, the redoubt would be able to support six, thirty-two-pound guns. These guns, with a range in excess of a mile, would be a strong defense against enemy forces.
Constructing such a massive redoubt required back-breaking work by hundreds of American soldiers. The soldiers chipped away at dirt and massive rocks left by glacial movement by hand using shovels and pickaxes. Before the completion of the redoubt, however, the Joint Occupation Agreement was signed by the United States in Britain in November of 1859. The two sides agreed to settle the boundary dispute through diplomacy, while each maintained a presence on the island.
Only three guns were ever placed on the redoubt, and they were used for ceremonial purposes. Today, you can walk the remnants of this great feat of engineering and look out to where British naval ships used to harbor, but instead of these ships you may spot migrating orcas or soaring eagles.