The invasion of Guadalcanal, Operation Watchtower, by sixteen thousand United States troops began on 7 August, 1942 and was the first American offensive of the war. Additional amphibious attacks simultaneously assaulted the islands of Florida, Tulagi, Gavutu and Tanambogo.
Initially, only unarmed Japanese construction and support personnel occupied Guadalcanal itself, allowing the Americans to come ashore almost unhindered. But Japanese reinforcements arrived on the island from Rabaul to destroy the Americans (Operation Ka-Go).
These convoys and the land battle on Guadalcanal became magnets for naval activity on both sides. This resulted in seven naval battles:
The land battle hinged around the airfield which the Americans named Henderson Field, a muddy airstrip hanging onto the edge of the island, and considered "an unsinkable aircraft carrier". The Japanese suffered 24,000 casualties, the Americans 6,000.
Extreme desperation characterized the ground fighting; only three of the defenders surrendered. American authorities declared Guadalcanal secure on 9 February, 1943, after more than six months of combat.
See Operation Ke, and Operation Shoestring.