Where did the battle for Guadalcanal take place, from which the US offensive began?
On the Solomon Islands. The Guadalcanal Campaign, also known as the Battle of Guadalcanal and codenamed Operation Watchtower was a military campaign fought between 7 August 1942 and 9 February 1943 on and around the island of Guadalcanal in the Pacific theater of World War II. It was the first major offensive by Allied forces against the Empire of Japan.