This weekend is Labor Day Weekend in the United States. It is a public holiday on the first Monday of September. The holiday is to celebrate the American labor movement and its contribution to the Untied States. Labor Day became a federal holiday in 1894. While you are enjoying your BBQ, picnics, and other end of summer celebrations take a moment and remember the workers and activist who helped shape America’s work force. Here are 5 Historically Important Sites to the American Labor Movement.