A single-issue party (exclusively focused on abortion).
As far as I remember the U.S was allied with South Korea, and other European and capitalist countries and they opposed The Soviet Union, North Korean and communist countries.
One can say that dominating fire was one major breakthrough. Men were already using rock tools in this age and it was an amazing breakthrough in history of man, but learning how to dominate fire was a game changer. It made them live longer, since they had a way to scare the predators, make light at night and to defrost meat.
I'd say pollution or disease.
