Your lecture on the Roaring Twenties in the United States could use these two graphs. The first graph details the annual immigration and Quota Laws from 1907-29, and compares them to the McCarran-Walter Act of 1952. The second graph shows the cost of a Model T Ford and the changes from 1908-1924. Though too brief to substantiate an entire lecture, these slides could be helpful in the context of a class discussion.