The policies of containment used during the Cold War (which were the Truman Doctrine and the Eisenhower Doctrine) both used the economy to help out other countries to stop the spread of communism. The Eisenhower Doctrine in addition used military forces.
The Bush Doctrine is different because it actually tried to implement democracy into other countries (such as the middle east) in an attempt to stabilize the government.
Because factory owners could pay children less money than they paid adults.
To find jobs.. back then you could get a job with little or no skill at all. the idea of having a better job was appealing to manyfarmers and immigrants.
The first universal credit card, which could be used at a variety of establishments, was introduced by the Diners' Club, Inc., in 1950.
