On Wednesday, April 19, 1865, Ralph Waldo Emerson stood before his neighbors in Concord, Mass., and gave the speech of his life.

It is all the more remarkable for the fact that he could not have begun writing it earlier than the previous Saturday, for it was on that morning that Abraham Lincoln had died. And in Concord on the 19th—a date ever before and since the town’s most joyous, for the memory of 1775—Emerson was eulogizing the fallen president.

Of the three greatest men whom providence has summoned to the presidency in our nation’s most critical hours, Lincoln alone seems to us totally self-created—which is to say the most quintessentially American. Washington, though denied a formal education by the early death of his father, was always a highly cultured aristocrat; FDR, a scion of great wealth and family, was a product of Groton and Harvard. Lincoln, with not a year in total of scattered episodes of backwoods schooling, was entirely an autodidact.

Yet he had, to the last day of his life, a seemingly limitless capacity for growth, and became, among his other astonishing accomplishments, the greatest prose stylist ever to occupy the presidency. Indeed, in 272 words at Gettysburg, and in the 703 words of his second inaugural address—with but 11 days to live—he defined the war, and the future of the American Union, in speeches no other president has ever quite touched.

It is this Lincoln who is captured in my very favorite one-volume biography, that by David Herbert Donald. It focuses narrowly and even relentlessly on the man himself, and surely it is the man we seek most ardently to understand. In that sense, if a definitive life of Lincoln is even possible, Donald’s is that book: the indispensable biography of the indispensable man. I commend it not merely to every financial advisor but to every American.

For myself, at 7:22 a.m. this April 15—the sesquicentennial to the very moment of Lincoln’s death—I’ll be reading Emerson’s magnificent eulogy once again. I feel like I owe it to someone.

©2015 Nick Murray. All rights reserved. Reprinted by permission. Nick reviews current books, articles and research findings in the “Resources” feature of his monthly newsletter, Nick Murray Interactive. To download the most recent sample issue, visit www.nickmurray.com, and click on “Newsletter.”