The war in the north was effectively stalemated for the next few years. The British successfully defended Newport, Rhode Island against a Franco-American invasion attempt that was frustrated by bad weather and difficulties in cooperation between the allies. British and Indian forces organized and supported by Sir Frederick Haldimand in Quebec began to raid frontier settlements in 1778, and Savannah, Georgia was captured late in the year. In response to the frontier activity Washington organised a major expedition against the Iroquois in the summer of 1779. In the Sullivan Expedition, a sizable force under Major General John Sullivan drove the Iroquois from their lands in northwestern New York in reprisal for the frontier raids.