Final answer:
Lincoln's message was one of unity, national dedication, and the preservation of democracy.
Step-by-step explanation:
Lincoln's message to the Union when he gave the Gettysburg Address was one of unity, national dedication, and the preservation of democracy.
He emphasized that the United States was a government 'of the people, by the people, for the people,' highlighting the importance of a government that serves the interests of its citizens.
Lincoln sought to inspire the nation by reminding them of the sacrifices made by the soldiers in the Civil War and the need to ensure that the principles of equality and liberty were upheld.