We Were the Mulvaneys by Joyce Carol Oates

The Mulvaneys of High Point Farm in Mt. Ephraim, New York, are a large and fortunate clan, blessed with good looks, abundant charisma, and boundless promise. But over the twenty-five year span of this ambitious novel, the Mulvaneys will slide, almost imperceptibly at first, from the pinnacle of happiness, transformed by the vagaries of fate into a scattered collection of lost and lonely souls.