The United States borders three of the world’s named ocean basins: the Atlantic, the Pacific, and the Arctic. The contiguous states face the Atlantic and Pacific, and the Gulf of Mexico is part of the Atlantic system; Alaska’s northern coast reaches the Arctic Ocean through the Beaufort and Chukchi seas.
NOAA’s Office of National Marine Sanctuaries describes America as a nation that “touches three of the great ocean basins and the massive inland waters of the Great Lakes.” (The Indian and Southern Oceans do not border U.S. territory.)
Source: NOAA Office of National Marine Sanctuaries — The Making of a Maritime Nation.