Answer:
In the period 1750 - 1900, there were many revolutions around the world, that changed the global social, economic, and political landscape. Many of these revolutions had one thing in common: they were led by people who demanded the end of monarchies or dictatorships, and the establishment of more republicans forms of government.
We had three good examples to confirm this: the American Revolution, the French Revolution, and the Latin American Revolutions. They all occurred from the end of the XVIII century to the first three decades of the XIX century. They all wanted to end a monarchical form of government, and to replace it with a Republican form of government.
The American Revolution is the clearest example, it resulted in the secession of the American Colonies from the United Kingdom, and the formation of a new federal republic: the United States of America.
<span>"In U.S. history, the term progressivism refers to a broadly-based, liberal reform movement that reached its height early in the 20th century. The initial progressive movement arose as an alternative to the conservative response to the vast changes brought by the industrial revolution. Contemporary progressives continue to embrace concepts such as environmentalism and social justice."
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Source(s):<span>Wikipedia
http://en.wikipedia.org/wiki/Progressivism
http://en.wikipedia.org/wiki/Progressivism_in_the_United_Stat</span>
Because pollution was blocking sunlight.
