According to Frederick Jackson Turner, the change of a stable and civilized way of life in European cities, towards the change of life in the prairies, in wild territory, produced in the Colonists an emergence of the adventurous spirit, full of a new vitality , and formed that American spirit so different from the British. This meant that independence was necessary to develop self-sufficiency and individualism, to advance in a frontier and wild territory. However, over the years, he changed his point of view, and thought that it was necessary to return to a systematized and organized way of life, to ensure that resources would last.
The accomplishments of the Lewis and Clark Expedition were extensive. It altered the imperial struggle for the control of North America, particularity in the Pacific Northwest. It strengthened the U.S. claim to the areas now known as the states of Oregon and Washington.
During times of civic unrest such as riots, the national government can summon the national guard to its help if it thinks that the local forces cannot stop it or if the riots are going out of hand.
Transistor computers were built. The first mobile phones were built. Computers using vacuum tubes were invented. Computers with integrated circuits were invented. The World Wide Web was created.
