A well-written biography of our most influential jurist. Smith (George Bush's War, 1992, etc.) attributes the chief justice of the Supreme Court's lifelong commitment to national, as against state, power to his service in Washington's army during the American Revolution, including the bitter winter at Valley Forge. After the Revolution, he slowly built a lucrative law practice in Richmond, Va., while occasionally serving in state office and avidly supporting the Federalist Party; the extent to which political disagreement fostered Marshall's fully reciprocated animosity toward his second cousin, Thomas Jefferson, is unclear. As an emissary to France, Marshall showed sound judgment in the diplomatic crisis known as the XYZ Affair; he subsequently served with distinction in Congress and as secretary of state before President John Adams appointed him chief justice at age 45. Marshall used his enormous political skill and personal appeal to unite the Supreme Court in forging its most important early decisions, including Marbury v. Madison, which established the federal judiciary's authority to determine the constitutionality of acts of Congress and the president; McCulloch v. Maryland, which declared the supremacy of federal over conflicting state law; and the Dartmouth College case, which made possible the development of the corporation as an engine of economic activity. It is hard to imagine the course of American history had these decisions not been as lucidly and forcefully articulated as they were by Marshall, so the sobriquet ""definer of a nation"" is justifiable hyperbole. The book is flawed, however, by a failure to discuss the element of self-interest that often accompanied Marshall's political and jurisprudential values. Moreover, although Marshall emerges as an attractive combination of conviviality and pragmatism, his role in what would now be called a dysfunctional family might have been worth exploring. Borders on hagiography, but learned and readable.