Read the passage below: But, in a larger sense, we can not dedicate-we can not consecrate-we can not hallow-this ground. The brave men, living and dead, who struggled here, have consecrated it, far above our poor power to add or detract. The world will little note, nor long remember what we say here, but it can never forget what they did here.
According to Lincoln, what is his purpose in giving the speech?

to ask citizens to enlist in the military
to convince voters why he should be reelected
to remember those who lost their lives in the battle
to call for the Confederate states to surrender