However, “Lincoln and the Abolitionists” never quite gels. As the bifurcated title and subtitle suggest, it lacks a clear focus. In addition, there are numerous historical errors, some trivial (the Northwest Ordinance was adopted in 1787, not 1795) but many egregious. Instead of giving African-Americans the right to vote in 1821, as Kaplan states, New York in fact disfranchised nearly all of them. It is astonishing to read that Tennessee, one of the 11 states of the Confederacy, “never left the Union” or that the Compromise of 1850 (rather than the Kansas-Nebraska Act of 1854) repealed the Missouri Compromise, a milestone on the road to civil war.

Along with Lincoln, the book’s other key figure is John Quincy Adams. Beginning in 1830, after serving a term as president, Adams was elected several times to the House of Representatives, where he led the fight against the “gag rule,” which barred discussion of abolitionist petitions. Kaplan is mostly interested in Adams in order to contrast him, an “antislavery activist,” with Lincoln, an “antislavery moralist” — someone who spoke against slavery but failed to take action against it. Adams believed in the citizenship of free blacks; Lincoln did not. Lincoln “put all his hopes” for ending slavery in the American Colonization Society, which advocated encouraging or requiring free blacks and emancipated slaves to emigrate to Africa, while Adams considered colonization impractical and unethical. Adams insisted that in a war the president could invoke his power as commander-in-chief to abolish slavery; Lincoln moved toward emancipation only slowly and reluctantly, and when he did issue the Emancipation Proclamation, he exempted about three-quarters of a million slaves in parts of the Confederacy and in the four border slave states that remained in the Union. Lincoln’s reluctance to act decisively against slavery, Kaplan argues, reflected both personal qualities — “compromise and gradualism were in his blood” — and a strong devotion to the Constitution, despite its provisions protecting slavery. But the deepest reason for his hesitation was racism: Lincoln believed that America “was and always should be a white man’s country.”

Image Portraits of “Eminent Opponents of the Slave Power.” Credit... Bettmann Archive, via Getty Images

Kaplan is correct to direct attention to Lincoln’s strong advocacy of colonization during the 1850s and the first two years of the Civil War, something many admirers play down or ignore. But as a full portrait of Lincoln’s views on slavery and race, the account is, to say the least, one-dimensional. Kaplan’s treatment of Lincoln’s relationship with abolitionists, who demanded an immediate end to slavery, is a case in point. Lincoln was not an abolitionist and never claimed to be one. But it is untenable to write, as Kaplan does, that Lincoln “detested” abolitionists and “wanted nothing to do” with them. Lincoln considered himself part of an antislavery movement that also included abolitionists. He understood that without their effort to change public opinion, his own more moderate antislavery politics, which focused on preventing slavery from expanding, not its abolition, would be impossible.

In 1856, Republicans in northern Illinois nominated Owen Lovejoy to run for Congress. The brother of the antislavery editor Elijah P. Lovejoy, who had been murdered by a mob in 1837, Owen Lovejoy was himself an outspoken abolitionist. A group of conservative Republicans, including close friends of Lincoln’s, proposed to put forward an independent candidate. Lincoln instructed them not to do so, not simply because he believed in party unity, but because of the “great enthusiasm for Lovejoy” that his supporters would “carry into the contest.” To use a modern idiom, Lincoln understood that abolitionists were part of the Republican Party’s base. And despite sharp criticisms of Lincoln, most supported his election in 1860. As Manisha Sinha notes in her recent history of abolitionism, Wendell Phillips greeted his victory by exulting, “for the first time in our history, the slave has chosen a president.” All this is absent from “Lincoln and the Abolitionists.”