"When Washington Shut Down Wall Street" unfolds like a mystery story. It traces Treasury Secretary William Gibbs McAdoo's triumph over a monetary crisis at the outbreak of World War I that threatened the United States with financial disaster. The biggest gold outflow in a generation imperiled America's ability to repay its debts abroad. Fear that the United States would abandon the gold standard sent the dollar plummeting on world markets. Without a central bank in the summer of 1914, the United States resembled a headless financial giant. Will…