When it comes to early American history, few beat Gordon Wood, and this new book looks like a great summing of the period, Gordon S. Wood demonstrates in “Empire of Liberty,” his superb new account of America’s pivotal first quarter-century, these inchoate Americans were audacious from the very start. Timothy Dwight, the president of Yale, brazenly asserted that the United States was destined to be “God’s own Word.” Madison called America an Arcadian “paradise,” while Thomas Jefferson labeled the nation “the world’s best hope.” And when they gazed over at the decadent, decaying monarchies of France and England, Americans concluded they were on the cusp of a new age, destined to be “an asylum to the good, to the persecuted and to the oppressed.” Wood’s central characters are familiar too, but presented in admirably nuanced portraits. We see the austere George Washington, whose inordinate strength was his realism; we see the perplexing Thomas Jefferson, who so eloquently championed