Answer: The main message was that Democracy and the United States would last, in spite of the Civil War.
The Gettysburg Address is a speech that U.S. President Abraham Lincoln delivered during the American Civil War at the dedication of the Soldiers' National Cemetery in Gettysburg.
Lincoln described ours as a nation "conceived in Liberty, and dedicated to the proposition that all men are created equal," and represented the Civil War as a test that would decide whether such a nation, the Union sundered by the secession crisis could endure.