The U. S. carried on a "island-hopping campaign in order to what?

The US carried on an "island-hopping campaign" in order to dismantle Japanese military holdings in the Pacific Ocean during the Second World War. When the US entered war with Japan in 1942, it was set to be a unique war due to the vast distance between both countries (the Pacific Ocean). The Japanese had taken a large number of islands in the Pacific that they used to refuel ships, planes, and wage war against the US. Rather than launching an all out war on the Japanese mainland (which would have been near impossible due to the Japanese presence throughout the Pacific and even into Alaska), the US had to piece-by-piece take out these islands by island-hopping; US marines would arrive at an island, fight the Japanese, take the island, and set up their own air bases and ship docks.