The topics that are the focus of your paper seem to take US history from the time of early imperialism under Teddy Roosevelt in the first decade of the 1900s to the time when the Cold War was beginning to heat up in the late 1940s and early 1950s.
So with those two larger topics in mind - imperialism and the Cold War, you may want to talk about the development of the first:
* how the United States became an empire and expanded its territories to include the Panama Canal, control over the Caribbean, with heavy influence over Latin America and the Philippines. Include why the US would do this - for world power in competition with other empires, and for control of resources which would aid our economy
And the beginning of the Cold War second:
*how our goal of expanding our control as an empire changed into a foreign policy of containing the Soviet empire's expansion, and controlling more resources and influencing other countries with economic and military aid so they wouldn't be communist, or so the Soviet Union would not gain access to their resources.