Nineteenth-century editorial cartoons often pictured government and industry hand-in-hand. Yet as early as 1889 Texas had enacted an antitrust law to curb the power of monopolies, and in the first years of the industry that would bring untold riches to the state, the attorney general used that law against oil trusts to a surprising extent. Ironically, for most of the first twenty-five years following the enactment of the Sherman Antitrust Act, federal enforcement efforts were extremely limited, leaving the field to the states. Texas was one of several states that had strong antitrust laws and whose attorneys general prosecuted antitrust violations with vigor. Political ambition was a factor in the decisions to investigate and prosecute cases against a highly visible target, the petroleum industry, but there was also a genuine belief in the goals of antitrust policy and in the efficacy of enforcement of the laws. In Broken Trusts, Jonathan Singer offers the definitive study of the formative period of antitrust enforcement in Texas. His analysis of the state attorney general’s use of antitrust law against the oil industry in this time of transition from agricultural to industrial society provides insights into the litigation process, the gap between the rhetoric of trust-busting and the reality of antitrust enforcement, and also the changing roles of state government in the late nineteenth and early twentieth centuries. The experience of Texas undermines the view that federal action has always dominated antitrust enforcement efforts and that antitrust litigation against Standard Oil was ineffectual. Rather, the results of the Texas attorney general’s litigations suggest that some states took their role in the dual enforcement scheme seriously and that the measure of success of antitrust enforcement goes beyond the amount of monetary penalties collected and the number of companies permanently ousted from a state. This volume will be valuable to those interested in the effects of the Sherman Antitrust Act, as well as those concerned with the evolution of the Texas attorney general’s office.