“I imagine that one has to be at least 90% damn fool to plunge headlong into every hopeless fight that calls for volunteers,” Harold L. Ickes wrote in 1930. One can see why he thought this at the time. The 56-year-old Ickes had lent formidable political energy to a succession of ill-fated progressive Republican candidates for the Chicago mayoralty as well as for the Presidency. Two years later an invitation to organize a league of Western Independent Republicans for Roosevelt revived his battered political spirits. Ickes would spend 13 years as Secretary of the Interior, 12 of them dutifully serving Franklin Roosevelt. T. H. Watkins’s Righteous Pilgrim masterfully dramatizes the long political life of this irascible New Dealer.

Ickes remade a cabinet department that had historically viewed the American landscape as a resource ripe for exploitation. Though not a radical preservationist, he placed more value on undisturbed wilderness than on profit-making opportunities.

But Ickes’s role under Roosevelt was much more than guardian of the nation’s forests and national parks. He ran the Civilian Conservation Corps, which put up to 500,000 people to work on the nation’s infrastructure, and the Public Works Administration, which was responsible for construction projects ranging from small-town post offices and libraries to the Hoover Dam and Lincoln Tunnel.

His was a clear and constant voice for the rights of underprivileged Americans; it was Ickes, for instance, who introduced the black opera singer Marian Anderson’s controversial concert at the Lincoln Memorial by declaring that “genius draws no color line.”

If Ickes seemed to serve as the self-appointed conscience of the administration, he just as often functioned as its hatchet man. A master of political invective, he spared no challenger his razor tongue, not from the left—he diagnosed Huey Long as suffering from “halitosis of the intellect”—nor from the right, as he dressed down every Republican presidential candidate from Herbert Hoover to Wendell Willkie.

Watkins explores Ickes’s turbulent personal life in great depth. His unhappy childhood with an alcoholic father in Altoona, Pennsylvania, set him on an extended spiral of depression that continued through his rocky first marriage. The infidelity and violence that punctuated that bond were nowhere evident in his scandalous 1938 remarriage to a woman nearly 40 years his junior. As a senior citizen Ickes finally found domestic happiness, doting on his young wife and fathering a son and daughter.

Yet it is another fruitful partnership—the one between Ickes and Roosevelt—that lies at the heart of Righteous Pilgrim . The two men were not always on good terms—Ickes regularly threatened to resign over bitter turf fights with FDR cronies like Harry Hopkins and Henry Wallace—but their mutual loyalty seemed to grow over the years. Roosevelt conspired to keep Ickes’s elopement to Ireland under wraps, wiring the newlyweds that ABILITY OF AMERICAN GOVERNMENT TO KEEP A SECRET FIRMLY ESTABLISHED FOR THE FIRST TIME IN HISTORY. And in a touching coda to their friendship, Roosevelt again refused Ickes’s