I don't really know--someone from outside the United States might have a better answer. However, I will say that the United States is known for:
--Jazz music
--Niagara Falls, and other natural wonders (the Grand Canyon, Yellowstone National Park).
--The hamburger "as we know it."
--Coca-Cola.
--Mark Twain.
--Walt Disney World.
--The Apollo space program (which culminated in the moon landings).
--The Constitution of the United States.