The possibilities for slavery expansion were almost endless. Douglas would have done these things, but he couldn't subscribe to the slave code. And o… - Harry V. Jaffa

That was a decisive moment in Lincoln’s career, and that’s the situation he faced when he got up to give his “House Divided” speech on June 16th of 1858. It was a crisis of his own career. It was also, in my opinion, the gravest crisis this country has ever faced, because the greatest danger to the future of the country came not, I think, from the pro-slavery argument, but from the morally neutral argument of Douglas. And that’s a long story and you’ll find it all spelled out in great detail in my book, which I hope you will read with great care.

While slavery meant Egypt, and slavemasters meant Pharoah, America itself remained the promised land. The slaves knew that it was not in Africa, Europe, or anywhere else that a nation had been founded upon the self-evident truth that all men are created equal. It was their destiny to cross over jordan here, and to make their decisive contribution to the human story here, by partaking of that new birth of freedom that alone could vindicate the cause of all human beings everywhere.

According to Abraham Lincoln, public opinion always has a central idea from which all its minor thoughts radiate. The central idea of the American Founding—and indeed of constitutional government and the rule of law—was the equality of mankind. This thought is central to all of Lincoln's speeches and writings, from 1854 until his election as president in 1860. It is immortalized in the Gettysburg Address.