“‘The moment I was president,’ sighed Abraham Lincoln in the spring of 1864, people ‘seemed to think . . . I had the power to abolish slavery.’ He didn’t. And despite the demands, the pressure, and even the bullying of abolitionists, politicians, and journalists, he was correct. American slavery, as it existed before 1861 and the outbreak of the Civil War, was a creation of state statutes. In an era that knew nothing about an ‘incorporation doctrine’ requiring the conformity of state law with the federal Constitution, a jurisprudential firewall separated the authority of the federal government (and of Lincoln, as its executive) from the states. In strict constitutional terms, then, Abraham Lincoln’s hands were tied on the subject of slavery. ‘Before I could have any power whatever,’ he explained, ‘I had to take an oath to support the Constitution of the United States and execute the laws as I found them.’

That did not mean that Lincoln was indifferent to the hideous wrong of enslaving other human beings. ‘The slavery question often bothered me as far back as 1836 to 40,’ he remembered. ‘I was troubled and grieved over it.’ And in 1837, as a newly minted Illinois state legislator, he had sponsored a resolution condemning slavery as ‘founded on both injustice and bad policy.’ But even then, he acknowledged that the firewall between federal and state authority gave the federal government ‘no power, under the constitution, to interfere with the institution of slavery in the different States.’

True as it was that Lincoln hated especially ‘to see the poor creatures hunted down and caught and carried back to their stripes and unrequited toil,’ and  described himself as ‘one who abhors the oppression of negroes,’ his only political option in the 1850s was to ‘oppose the extension of slavery’ into the western territories of the old Louisiana Purchase. Even as president, Lincoln candidly declared, ‘I am naturally anti-slavery,’ and he believed that ‘if slavery is not wrong, nothing is wrong.’ But he had ‘never understood that the Presidency conferred upon me an unrestricted right to . . . practically indulge my primary abstract judgment on the moral question of slavery.’

The Civil War altered that landscape for him…”