Final answer:
The central idea of Lincoln's Gettysburg Address is that the sacrifices during the Civil War were essential for upholding the nation's foundational principles of equality and democracy.
1 is correct
Step-by-step explanation:
The central idea of President Abraham Lincoln's Gettysburg Address is that the sacrifice of the soldiers who died in the Civil War was crucial in preserving the nation founded on the principle that all men are created equal, as stated in the Declaration of Independence. During the dedication of the Soldiers' National Ceremony at Gettysburg, Lincoln honored the soldiers who fought and died, and he emphasized the need for the living to continue the fight for a new birth of freedom, ensuring that a government 'of the people, by the people, for the people' does not perish from the earth. The speech not only commemorated the fallen at Gettysburg but also reaffirmed the Union's commitment to the principles of equality and democracy.
While Lincoln did establish his credibility as President and used various rhetorical devices, these were not the central ideas. The impact of Lincoln's message was indeed strengthened by his speech, yet that is an outcome rather than the main theme. Therefore, the most fitting answer based on President Lincoln's words is option 1: The sacrifice of the people who died in the Civil War made it possible to protect the rights guaranteed to all men in the Declaration of Independence.