In "Founding Brothers: The Revolutionary Generation," Joseph J. Ellis highlights that the core of America's foundation lies not just in its declaration but in the ongoing debate regarding its interpretation. Lincoln emphasizes that the nation was established based on the philosophical proposition articulated by Thomas Jefferson in 1776, reflecting a commitment to ideals of liberty and democracy.

This assertion points to a deeper, intrinsic conflict about the meaning of freedom and equality, illustrating that America's identity is shaped by the differing perspectives on these foundational principles. This continuous struggle to define and live up to the nation's founding ideals remains essential to American history and democracy.