The heading is as follows:

To what extend was late nineteenth-century and earl twentieth-century United States expnsionism a continuation of past United States expansionism and to what extend was it a departure?

I have developed it to that it is asking if imperialism is a continuation or a departure from westward movement, I believe that it is a little of both but more on the side of continuation..

If anyone has any ideas of how to make the thesis, and some evidence or web pages with evidence... It would be greatly appreciated. Thanks