In 1894, Felix Frankfurter arrived in the United States from Austria as an 11-year-old who spoke no English. Less than a dozen years later, he graduated first in his class from Harvard Law School. He kept climbing at that speed through a career that placed him at the center of national affairs for more than half a century. Frankfurter was a celebrated advocate for progressive causes, a legendary Harvard law professor, a close adviser of President Franklin Roosevelt during the New Deal, and a Supreme Court justice for 23 years. There, his unquenchable energy, powerful intellect, and sometimes overbearing manner made him a force on the bench—but also a poor coalition builder. He had long believed that the judiciary should leave social policy to Congress. As the Court became more liberal, especially under Earl Warren, Frankfurter’s advocacy of judicial restraint severely disappointed progressives. The notable exceptions were cases involving racial discrimination: for example, he played a key role in achieving a unanimous decision in Brown v. Board of Education, the 1954 verdict that ruled that racial segregation in schools was unconstitutional. With some prescience, he argued that progressives would come to rue a Court that was active in making policy when it was again staffed with conservatives. Such a Court now holds sway, making this authoritative, albeit overly detailed biography of an extraordinary figure in American history and jurisprudence very timely.