Before Chernow became the biographer of the American heroes hiding in our wallet — Ulysses S. Grant, George Washington, and most famously Alexander Hamilton — he was a chronicler of Morgans, Warburgs and Rockefellers. Chernow integrates Twain’s cupidity into his strange and dark but also enlightening and entertaining book. He shows how Twain’s fast, rowdy style made his name and complicated much of his life’s work. Twain died famous. He didn’t die particularly happy.