What ocean is on the East Coast of the United States?

The Atlantic Ocean is on the East Coast of the United States. It borders states from Maine in the north through Florida in the south. The Pacific Ocean is on the West Coast, bordering California, Oregon, Washington, and Alaska (and Hawaii sits in the Pacific). The Gulf of Mexico, an arm of the Atlantic, borders the southern coast of states like Texas, Louisiana, Mississippi, Alabama, and Florida. The United States is the only country with significant coastline on three oceans (Atlantic, Pacific, and Arctic, via Alaska). The Indian Ocean does not border the United States. This question is on the citizenship test in part because geographic knowledge is part of basic civic literacy.