On March 4, 1861, retiring president James Buchanan remarked to his successor, "Abraham Lincoln, If you are as happy in entering the White House as I shall feel on returning [home] to Wheatland, you are a happy man indeed." Few of our presidents have assumed office with a more distinguished record of public service than Buchanan. But despite serving as secretary of state under James K. Polk and ambassador to Great Britain under Franklin Pierce, he did not have the understanding or the diplomatic skills to deal effectively with the divisive issues that confronted our country at that time. In fact, he left office with the nation very close to civil war.

Although Lincoln had little formal education and his performance as a one- term congressman had not been notable, he had been involved in public life for many years. He enjoyed grappling with difficult issues. As our only Civil War president, Lincoln expanded the role of the office in some areas but treated others, including foreign affairs, in the conventional ways of his predecessors. He is usually regarded as our greatest president.

Why have some presidents been successful in certain ways but not others? Why are some regarded as complete failures? What role have social, economic, cultural, demographic, and political factors played throughout the 42 presidencies of our history? Just in time for the presidential election year, an outstanding and provocative overview of the American presidents, seen in the context of their times, has just been published. The Reader's Companion to the American Presidency, edited by Alan Brinkley and Davis Dyer, features authoritative and insightful essays written by many of our most distinguished historians on the lives and careers, and particularly the administrations, of each occupant of the office. As the editors note, It is not just the gap between image and reality that makes American presidents elusive and intriguing figures. It is also the problem that both contemporaries and historians experience in trying to separate the president as a person from the things done in his name. They point out that from the founding of the Republic it has often been difficult to separate a president's own actions and achievements from those of his associates and political allies.

It is fascinating to realize how close many of our elections have been. Thomas Jefferson did not become president for his first term until he was elected on the 36th ballot in the House of Representatives. Once elected, as historian Joyce Appleby notes, Jefferson turned himself into an agent of change profound, transformative change in the social and political forums of his nation . . . Indeed, because his eight years in office were followed by sixteen more from his closest associates, James Madison and James Monroe, it is not too much of an exaggeration to say that Jefferson was the nineteenth century's most influential president. We usually regard Theodore Roosevelt as our first modern president, but Walter Lefeber points out that the self-effacing William McKinley, who worked quietly behind the scenes, can claim that distinction. McKinley, not Roosevelt, was the first modern U.S. president, modern in the sense of being a pioneer in manipulating the new technology of telephones and movies to enhance his power; a trailblazer in exploiting the modern powers of the presidency, especially in foreign affairs; the initial chief executive when the nation turned from acting continentally to acting globally. As a congressman, McKinley became a powerful political force because of his mastery of the tariff issue. He recognized that the tariff was the key to both the creation of immense economic power by great corporations . . . that could be protected from foreign competition, and also to the unlocking of corporate wealth for the support of ambitious politicians.

Both Michael Kazin writing about John F. Kennedy and Robert Dallek on Lyndon Johnson agree that our direction in Vietnam would not have been different in a JFK presidency. Kazin says, In recent years, some writers have maintained that JFK at the time of his death was bent on withdrawing from Vietnam. If he had lived, goes the argument, the long ordeal in Indochina would have been avoided. The bulk of the evidence refutes that contention. Dallek notes that Kennedy was leery of America's growing commitment to Vietnam . . . There is some evidence that JFK intended to remove U.S. advisors after he won reelection in 1964. But most of what he said and did indicated a determination to preserve South Vietnam freedom from Communism. Michael A. Stoe notes that, contrary to historical myth, Herbert Hoover was a whirlwind of activity when compared to other presidents who served during economic depressions, including Martin Van Buren, Ulysses S. Grant, Grover Cleveland, Theodore Roosevelt, and Warren Harding. Stoe points out that Hoover attempted to use the government to promote private and public action throughout his term to resolve the crisis sparked by the 1929 stock-market crash.

Its timelines, special features, important data boxes, and concise, well-written essays make this an invaluable reference. The Reader's Companion to the American Presidency offers historical perspective on the office in this presidential election year.

Roger Bishop is a regular contributor to BookPage.