B) The American industrial revolution had a major impact on Americans socially and economically.
This is the most effective thesis statement for a historical essay on the American industrial revolution. It introduces the idea that the revolution impacted Americans both socially and economically which clearly sets up the organization of the essay. It is also a statement that needs to be fully explained in order to develop the ideas. Option C is a statement of fact that would not need any development. Option A could work but it would be rather lengthy since it would need information about both the American and British industrial revolution.