The Korean War (1950-1953) began when the North Korean Communist army crossed the 38th Parallel and invaded non-Communist South Korea. As Kim Il-sung's North Korean army, armed with Soviet tanks, quickly overran South Korea, the United States came to South Korea's aid.
The best answer would be that "<span>The GNP rose dramatically and the United States changed from a debtor nation to a creditor nation" but the middle class definitely improved as well.</span>
