How to make this Thesis more clear?

This was a thesis I made for a take home APUSH test on our DBQ. We only had to make a good thesis and when I got it back, my teacher said he had to read it 3x to understand it better, so how can I make this more clear.</p>

Thesis: The U.S. would go through a new change in how they expanded in the years between 1890 to 1904 by focusing their attention on Central America and islands in the Pacific due to the massive demand of international business and trade along with the increasing influence of the rest of the world, continuing past expansion nd also beginning a new form of expansion, ending development of American land. </p>

Please hit this up ASAP so I know how to be more clear in my thesis statements.</p>