In North America, a second British attempt to capture Louisbourg succeeded. However, Pitt's pleasure over this was tempered by the subsequent news of a significant British defeat at Battle of Carillon. Towards the end of the year the Forbes Expedition seized the site of Fort Duquesne and began constructing a British settlement that would become known as Pittsburgh. This gave the British control of the Ohio Country, which had been the principal cause of the war.