It is striking how much recent scholarship on the mobility history of the United States has come to emphasize moments of relative motionlessness. More concerned with events in the halls of government than on the open road, historians have moved away from the nuts and bolts of transportation systems—the vehicles, the modes, and the infrastructure—to instead investigate how these networks have been shaped by larger political and social forces. Scholars have investigated these influences by highlighting how groups of Americans have codified, contested, or perceived the nation’s transportation system. By centering their studies on actors, rather than the actual systems, mobility scholars have framed their subjects in new ways and linked their subfield to political, legal, and social history.