What is the tone of Lincoln's "Gettysburg Address" speech?

The purpose of the Gettysburg Address was to dedicate a Civil War battlefield. Lincoln helped put the war in a larger context—that it was a war to protect government "of the people" from "perishing from the Earth." Lincoln uses the line "of the people" to frame the war as a war to protect the Founding Fathers' view of the nation. Lincoln takes a reverential tone when he states the people gathered at Gettysburg that November afternoon could not "dedicate" or "consecrate" that land any more than the soldiers who died there the previous July. Lincoln's concise speech always keeps the focus on the soldiers buried there. Also, Lincoln does not differentiate between the Confederate and Union dead—he seems to value them both equally.  

Lincoln gave this speech at a time when, while the Confederacy was losing power, the outcome of the war was in doubt. The war had already killed hundreds of thousands of men on both sides, and many in the Union were asking if the war was worth the cost. By framing the war as a battle to maintain the Founding Fathers' view of the nation, Lincoln states the Union's success is critical.