The United States of America is the opposite of the Confederacy.
United.
Untied
parted
Boise.
Antonyms are united, blended; there may be others.
The country that is exactly opposite the United States on the globe is Australia. If you were to draw a line from the center of the Earth through the United States, it would come out on the other side in Australia.
The opposite may be "useless." Context opposites may be unsuitable, or worthless, or unhelpful.
china maybe or japan???
The opposite of kimono could be western clothing or attire, such as shirts, pants, and suits commonly worn in countries like the United States and Europe.
The anagram words "united" and "untied."
The United States and the Soviet Union were the two countries on opposite sides during the Cold War. The Cold War ended in 1991.