The father of the billionaires Charles G. and David H. Koch helped construct a major oil refinery in Nazi Germany that was personally approved by Adolf Hitler, according to a new history of the Kochs and other wealthy families. The book, Dark Money," by Jane Mayer, traces the rise of the modern conservative movement through the activism and money of a handful of rich donors. The book is largely focused on the Koch family, stretching back to its involvement in the far-right John Birch Society and the political and business activities of the father, Fred C. Koch, who found some of his earliest business success overseas in the years leading up to World War II. One venture was a partnership with the American Nazi sympathizer William Rhodes Davis, who, according to Ms. Mayer, hired Mr. Koch to help build the third-largest oil refinery in the Third Reich, a critical industrial cog in Hitler's war machine. The Kochs' vast political network, a major force in Republican politics today, was "originally designed as a means of off-loading the costs of the Koch Industries environmental and regulatory fights onto others" by persuading other rich business owners to contribute to Koch-controlled political groups. In Ms. Mayer's telling, the Kochs helped bankroll - through a skein of nonprofit organizations with minimal public disclosure - decades of victories in state capitals and in Washington, often leaving no fingerprints.