Caro's volumes on the years of Lyndon Johnson have brought the enigmatic, misunderstood and nearly forgotten 36th president back into his rightful spot as one of the great leaders of the 20th century.

The scope of this book is much more narrow than the previous volumes, confining itself to LBJ's endless humiliations as John Kennedy's vice president, his sudden ascension to power through Kennedy's death and Johnson's astonishing grasp of control over the next few months.

Caro constantly apologizes throughout the book's 700 pages that so many issues await resolution until the fifth and final volume is completed.

But what is here is amazing, a Herculean feat of assembling information about Johnson, the Kennedys and the times in which they lived. For those who've never read a Caro book on Johnson, the level of detail may be a bit much to handle. Caro is nothing if not thorough.

Being able to avoid Vietnam, Robert Kennedy's death and Johnson's own exit from the presidency in disgrace allows Caro to focus on the nobler aspects of Johnson's character, especially in the dark days after Dallas. Johnson's quick thinking and ability to shepherd Kennedy's unfinished legislation through Congress is something to marvel and, by itself, assures him an honored spot in history.

As always, Caro balances the hagiography with facts inconvenient to the would-be mythmaker: LBJ's questionable business deals, some of which crossed the line into illegality; his scorn towards and obsession with Robert Kennedy.

This is a worthy successor volume to Caro's brilliant Johnson books. It's essential reading for any serious student of history.