University of Groningen
American History: Outlines: Latin America and the Monroe Doctrine
Outline of the Latin America independence movement and the accompanying spirit of U.S. support as expressed through the Monroe Doctrine.
Khan Academy
Khan Academy: World History: 1750 1900 Enlightenment and Revolution
We have none from this URL but there are some among embedded videos, although not all. For example, we have the two on Haitian Revolution and some on Napoleon. But I couldn't find those on imperialism.
University of Groningen
American History: Outlines: Presidency of Ronald Reagan
This site provides an extensive history of Reagan's administration including information on his presidential campaign, domestic policies, foreign policies, and domestic and international events of his presidency.