Which ocean borders the East Coast of the United States?

The Atlantic Ocean borders the East Coast of the United States. This vast body of water plays a significant role in the geography and climate of the eastern states, influencing weather patterns, trade routes, and cultural exchange. The Atlantic is not only the second-largest ocean but also the one that has historically shaped the development of the U.S., serving as a critical corridor for exploration and commerce.

The Pacific Ocean, while it is the largest ocean, lies on the West Coast of the United States and does not impact the eastern states. The Indian Ocean and Southern Ocean are located south and east of the U.S. and do not have any geographical connection to the East Coast. Hence, the Atlantic Ocean is the correct identification of the ocean that borders the East Coast. This understanding is key in a civics context, as it emphasizes the importance of geography in the nation's development.