In the United States, several national holidays are considered important, each one with its own significance. However, some of the most important national days in the U.S. are, Independence Day, Memorial Day (Last Monday in May), Veterans Day (November 11th), Martin Luther King Jr. Day (Third Monday in January), and Labor Day (First Monday in September). The importance of the national days varies depending on the person, some might see one day as more significant than others, but these days are widely recognized as important by most Americans.