Ex-Americas Great Diaspora

Describe the largest diaspora in your world. Why did they leave their homeland?
In year 2023 WWIII began. At first it was a conflict between 3 large arrays: the NATO, The Russia-China Alliance and the Mid-East Alliance for Islam. The war between countries stopped after the deployment of several nuclear warheads that were destroyed while travelling in the atmosphere by the US-Nato Defense Shield and the destruction of Pyongyang in a inside attack from what is thought to have been a rebellios party to the government. This quickly escalated in a World Civil War, with milions of violent protesters attacking their governments to stop the nuclear war. The attacks were sometimes aided by the military force and used military tactics and resources. The counter-attacks of the sovereign governments however were cruel and used tactics and weapons never seen before against civilians. The World Civil War lasted almost a decaded and totally disrupted world commerce and finance. During those years some tech companies affirmed their power over some states by managing and enforcing law with sperimental technologies for the repression of the rebel parties. Milions of lives were lost globally. Russia's dictatorship was also attacked from inside; in a desperate last move, having lost the substantial part of its military apparatus, the Russian establishment launced a total nuclear attack against United States probably hoping that the American Retailation would wipe away the rebels inside the country. But the Russian attack was, maybe by mistake, launched with an experimental new type of nuclear weapons several times more destructive than the most destructive ever tested. This produced in Messico a huge stray of craters large more than 1000 Km and immensely profound. This damaged scarred the planet and took a severe impact on the atmospheric stability of it. Even its rotation was affected. Biological life as it was previously known finished those days and never recovered. Almost 90% the Earth flora vanished in the sequent years. By 2050 the Planet was unrecognizable. The air was dense of nuclear dust, the water were contamined, the soil was poisonus. Sea gave no fish. All of the fauna was starving. Human presence on the planet dropped to a fifth. All government activities were suspended and the leaders were disbanded. Many powerful dinasties used the remaining bits of their fortunes to transfer themselves to the space colonies like the Moon and Mars. But the greatest diaspora was sustained by both south and north american people. The day of the Russian attack, 2 billions lives were immediately wiped away. Almost all of the remaining people that were spared by the explosion had to endure severe wounds, total lack of resources and the destruction of the infrastructures in the years to come. Having no resources, nothing to sustain themselves with an nowhere to go, the most of the remaining people became predators or prays. By 2050 territories of ex-America were almost completely unhinabited...