Battery Steele (U.S. Army Corps of Engineers Battery Construction #102) is a United States military fortification on Peaks Island, Portland, Maine in Casco Bay. Completed in 1942 as part of World War II, it is located on 14 acres (5.7 ha) on the oceanside area of the island, formerly part of the Peaks Island Military Reservation. It is named for Harry L. Steele, who was a Coast Artillery officer during World War I. It was armed with two 16-inch MkIIMI guns and, with a 12-inch gun battery at Fort Levett on Cushing Island, replaced all previous heavy guns in the Harbor Defenses of Portland. It was built to protect Casco Bay, particularly Portland harbor, from Kennebunk to Popham Beach in Phippsburg. According to Kim MacIsaac and historian Joel Eastman in An Island at War, “Battery Steele is