In 1855, with the United States at odds over slavery, the lawyer Abraham Lincoln wrote a note to his best friend, the son of a Kentucky slaveowner. Lincoln rebuked his friend for failing to oppose slavery. But he added: 'If for this you and I must differ, differ we must,' and said they would be friends forever. Throughout his life and political career, Lincoln often agreed to disagree. Democracy demanded it, since even an adversary had a vote. The man who went on to become America's sixteenth president has assumed many roles in our historical consciousness, but most notable is that he was, unapologetically, a politician. And as Steve Inskeep argues, it was because he was willing to engage in politics - meeting with critics, sometimes working with them and other times outwitting them - that he was able to lead a social revolution. In Differ We Must, Inskeep illuminates Lincoln's life through sixteen encounters, some well-known, some obscure, but all imbued with new significance here. Each interaction was with a person who differed from Lincoln, and in each someone wanted something from the other. While Lincoln didn't always change his critics' beliefs - many went to war against him - he did learn how to make his beliefs actionable. He told jokes, relied on sarcasm, and often made fun of himself - but behind the banter was a distinguished storyteller who carefully chose what to say and what to withhold. He knew his limitations and, as history came to prove, he knew how to prioritize. Many of his greatest acts came about through his engagement with people who disagreed with him - meaning that in these meetings, Lincoln became the Lincoln we know. As the host of NPR's Morning Edition for almost two decades, Inskeep has mastered the art of bridging divides and building constructive debate in interviews; in Differ We Must, he brings his skills to bear on a prior master, forming a fresh and compelling narrative of Lincoln's life. With rich detail and enlightening commentary, Inskeep expands our understanding of a politician who held strong to his moral compass while navigating between corrosive political factions, one who began his career in the minority party and not only won the majority but succeeded in uniting a nation.