How did the US respond to the Korean War?

The U.S tried to play the peace keeper but ultimatly was apart of the united Nations along with Austraila, Belgium, Canada, Colombia, Denmark, Ethiopia, France, Greece, India, Italy, Luxembourg, Netherlands, New Zeland, Norway, Philippines, South Africa 1950, South Korea, Sweeden, Thialand, Turkey, and the Unites Kingdom....I got all this from the site www.korean-war.com I'm trying to do a final prject on 7dif wars right now and I'm stuck...but not on that question so here ya go!!!...Jenny