White Southerners wanted the land, so the U.S. government granted it to them.
President Truman had the urge to use the atomic bomb against Japan because the American casualties would continuously rise unless the Empire of Japan surrenders. The thing that would make Japan surrender would be a cataclysmic event, and the bombing of Hiroshima and Nagasaki happened.
Ambush is all you have to say.
There have been many government actions meant to help unify the nation, but the greatest was done when the Articles of Confederation were replaced by the Constitution, since this action put into place a much stronger-central government and "united" the states.
After some early trading expeditions the first Dutch settlement was founded in 1615 fort Nassau on castle island along the hudson near present day Albany. The settlement served mostly as an outpost for trading in fur with the native lenape tribespeople but was later REPLACED BY FORT ORANGE.
Hope this helps.
