The Cold War. There was a build up of arms between the US and USSR.
It would be the "a. Social Security Administration" that was begun during the New Deal and still exists today, since many people rely on this in order to retire later in life.
The American civil war. The south is the blue, the north is red. The south didn’t need to capture any Northern Territory, whereas the north wanted to take over the south so that they could keep the states united, hence the Union.
Europeans around the 1500 to 1600 hundreds