"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. Now we are engaged in a great civil war, testing whether that nation or any nation so conceived and so dedicated, can long endure....It is for us, the be dedicated here to the unfinished work which they who fought here have thus far so nobly advanced. It is rather for us to be here dedicated to the great task remaining before this nation, under God, shall have a new birth of freedom—and that government of the people, by the people, and for the people, shall not perish from the earth."-President Abraham Lincoln, Gettysburg Address, July 1863
The passage above best serves as evidence of which of the following?
a. Union victory in the Civil War
b. The mobilization of the Union economy and society to wage the war
c. Unresolved questions about the power of the federal government and citizenship rights
d. The changing purpose of the Civil War