Final answer:
Lincoln's purpose in the Gettysburg Address is to underscore the foundational values of America and motivate the living to honor the fallen by dedicating themselves to the ideals of liberty and equality.
Step-by-step explanation:
Abraham Lincoln's purpose in the excerpt from the Gettysburg Address is to emphasize the nation's beliefs and ideals. In the Address, Lincoln recalls the formation of the United States, a nation built on the principle that 'all men are created equal,' and reflects on the ongoing Civil War as a test of the endurance of such a nation. He uses the dedication of the Gettysburg cemetery to honor those who died in the battle—not just as a commemoration of their sacrifice but as a call to the living to continue the fight for the principles that led to the formation of the nation and to ensure that 'government of the people, by the people, for the people, shall not perish from the earth.'