The Korean War. North and South Korea are still technically at war. An armistice was signed in 1953 to halt fighting, but no final treaty was signed, unlike after World War 2.
United States, NATO allies and South Korea fought against North Korea, who received aid from Chinese forces.
This an example of actual combat during the so-called Cold War between the United States and the Soviet Union between 1945-1991. The two sides had different ideologies (democracy vs. communism), which led to friction.
Increase of crops due to new innovations with the farming technique is one that comes to mind, not very sure about other factors though, sorry
African Americans have made numerous contributions to American society and culture. Many major cultural advancements from African Americans have come in literature, music, the arts, and many academic fields. African Americans have contributed enormously to the growth of different styles of music in the United States, one notable example is Jazz. African American artists were many of the earliest Jazz musicians and spread the musical style across the country and the world.
