From its inception more than half a century ago and for decades afterward, the Central Intelligence Agency was deeply shrouded in secrecy, with little or no real oversight by Congress--or so many Americans believe. David M. Barrett reveals, however, that during the agency's first fifteen years, Congress often monitored the CIA's actions and plans, sometimes aggressively.

Drawing on a wealth of newly declassified documents, research at some two dozen archives, and interviews with former officials, Barrett provides an unprecedented and often colorful...