The term "National Union" can refer to various political organizations or movements that aim to unite different groups within a nation for a common purpose. These unions often focus on promoting national interests, fostering unity, and addressing social or economic issues. They can be found in various countries and may represent a coalition of political parties or civic organizations. In the context of the United States, the National Union Party was a political party formed during the American Civil War. It aimed to support the war effort and promote the re-election of President Abraham Lincoln. The party was a coalition of the Republican Party and some War Democrats, emphasizing national unity during a time of division.