Gettysburg Address
At the dedication of the national cemetery at Gettysburg, Lincoln defined the war in a speech of little more than two minutes as a new birth of freedom and the defence of “government of the people, by the people, for the people”.

Mathew Benjamin Brady · Public domain · Source
A national cemetery for the Union dead was laid out at Gettysburg and dedicated on 19 November 1863. After the main speaker, Edward Everett, had spoken for two hours, Lincoln gave a short speech of some 270 words.
Beginning “Four score and seven years ago our fathers brought forth on this continent, a new nation, conceived in Liberty, and dedicated to the proposition that all men are created equal”, it ended with the resolve that the nation “shall have a new birth of freedom — and that government of the people, by the people, for the people, shall not perish from the earth.” By redefining the Union through the equality of the Declaration of Independence, it became one of the most famous statements of democracy. Five manuscript copies in Lincoln’s hand survive.