Final answer:
President Abraham Lincoln's statement refers to the founding fathers creating the United States on the principles of liberty and equality.
Step-by-step explanation:
By the line in bold from the Gettysburg Address, "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," President Abraham Lincoln clearly states that years ago, the founding fathers created the United States. This statement alludes to the nation's founding principles of liberty and equality, setting the stage for Lincoln’s message of unity and dedication to these principles amidst the Civil War. The address reminds listeners of the sacrifices made at the Battle of Gettysburg and emphasizes the importance of continuing the fight to ensure that the nation continues to embrace these founding ideals.