Retracing some of the main lines of FBI history, this part demonstrates how Bureau counterliterature was stamped by four distinct phases of the institution's developing Hoover era, altogether long enough to form a kind of police Mesozoic. It examines the glamorous and violent phase of Bureau history between the New Deal and the early 1940s. It then analyzes the changing shape of Bureau counterliterature during World War II, and does the same for the McCarthy period. Finally, it reviews the creative upheaval in Bureau counterliterature during the Black Power 1960s and 1970s. Author files and adjoining documents disclose that Hoover's FBI, the principal custodian of “lit.-cop federalism,” angled during all these phases to enlarge the state's ability to determine aesthetic value, scheming and networking like some National Endowment for Artistic Gumshoes. But these documents likewise show that his Bureau pursued changeable, art-educated enhancements of police tactics, converting varying currencies of literary capital into novel forms of criminological capital. Through both types of meddling, the Bureau paved the way to this book's second thesis, of necessity its most historically sprawling: The FBI's aggressive filing and long study of African American writers was tightly bound to the agency's successful evolution under Hoover.