The purpose of the immigration act of 1990 was to amend the Immigration and Nationality Act to change the level, preference system for admission, to provide for administrative naturalization, of the immigrants of US, and for other purposes.
4. They attacked and defeated all three at the same time.
Generally speaking, the Industrial Revolution inspired a "heightened" interest in Africa by European nations, since they looked to Africa to acquire most of their natural resources.
President Truman authorized the atomic bomb.