You will not find his name in the index of this book, but Freddie Gray, whom the New York Times reported in 2015 “ha[d] become the latest symbol in the running national debate over police treatment of black men,” feels deeply ingrained in the pages of Let Us Alone. Gray died in Baltimore “a week after he was chased and restrained by police officers, and suffered a spine injury, which later killed him, in their custody” ( New York Times, April 21, 2015). Michael Casiano has painstakingly researched the emergence of modern policing in Baltimore from the 1860s through the 1920s. This is a careful institutional story of the city police force and the direct extensions of its power, such as the jail and courthouse, but it also seeks to establish a much broader web of policing by including less formally connected organizations.

The author has designed a chapter structure around six “sites” of devising and carrying out policing: Baltimore’s city jail, “gathering spaces in which the city’s reformers colluded and schemed,” the public school, the street, the courtroom, and the home (13). Casiano’s object is not so much the city’s police force as its police state. For the author, this situation “emerges as much in punitive expressions of state violence as it does in the banal administrative functions of urban bureaucracy—two poles that organize the analysis of this book” (3). It is this perspective, focused on an assault on the independence and privacy of Black people, which helps the reader to seamlessly connect the criminalization of school truancy with a policing push to control the streets of Black Baltimore.

The author argues that “by the early twentieth century, Baltimore’s policing apparatus became primarily oriented around the subdual of Black freedom” (2). Casiano frequently punctuates the narrative with arrest and conviction data woven into the text or charted to drive home the quantitative evidence backing his claim that the processes and consequences of policing had a very disproportionate impact on Black people and their neighborhoods. The book begins and ends with stories from the everyday push for Black autonomy in Baltimore at the turn of the century. Joseph Johnson, arrested for larceny in 1902, tells the officer, “We ought to make examples of a few of you funny policemen and then, maybe, you’d let us alone” (1). In 1909, Baltimore’s Black newspaper, the Afro-American , invoked the phrase in an editorial: “let us alone without placing any hindrances in our pathway and let us take our chances among the people of the communities in which we live” (194). Arrayed against that demand was a formidable force of uniformed and plainclothes policemen; new Bureau of Investigation techniques used to identify and catalog criminals; a new public school system extending its reach into the home; the power of the court and jail; and the ambitions of politicians, reformers, and the press.

This book strays most from its promise when it strays from the stories of Black Baltimoreans—most prominently in the second chapter, which recounts the familiar battles between urban machine politicians and progressives, with the latter group exclusively and uniformly focused on social control in this study. The second half of the book contains the strongest chapters, wherein the reader finds a praiseworthy balance of the history of institutions with the stories of the individuals caught within them. The author also effectively humanizes these individuals by often focusing as much on their resistance, or at least their self-assertion, as on their victimization. This strength is best evident in chapter four, on policing the streets. Mainly focused on the cocaine trade, this chapter blends a compelling structural analysis of the varied components of the police state with gripping individual stories. After his arrest, the Baltimore Sun reported that “Big Dan” Waters was a saloonkeeper and drug dealer who was also a “hoodoo” practitioner and had a “conjure bag” in his safe alongside cash and cocaine (113). His arrest followed that of Alverta “Sweetie” Bailey, a domestic servant and petty dealer whom the press absurdly dubbed “Cocaine Queen” (115). The author deftly punctures both caricatures and illuminates the agency of his historical subjects. Bailey did not just implicate “Big Dan”; her testimony revealed that the police were profiting from the cocaine trade, a revelation that launched a major scandal.

Let Us Alone is far from the first book to assert that the modernization of policing was a proactive project to inextricably link criminality and blackness. The fundamental text here, which the author cites multiple times, is Khalil Gibran Muhammad’s The Condemnation of Blackness (2010), which focuses significantly on Philadelphia. Building upon this work, Casiano posits that “while many carceral histories are police histories set in cities, this book is an urban history of policing” (6). Muhammad co-edited The Journal of American History’s June 2015 special issue on “Historians and the Carceral State,” published just after Freddie Gray’s death, which announced the arrival of a field that has since continued to rewrite how modern political and social history intertwine, particularly at the city level. Subsequently, there has been an outpouring of urban work in this field over the last decade, and from Muhammad to Casiano, many have targeted the formative Gilded Age and Progressive Era.

As the case studies in this vibrant field continue to mount, reviewers could become cynical. As Casiano openly admits, “because policing is systemic, Baltimore is the best example—but so is every other city” (6). However, an emergent field seeking to understand the struggles of working-class people against the powers that develop to police them requires an array of case studies to carefully evoke variegated, fine-grained experience before scholars can synthesize broader conclusions that do justice to the many who shouted, let us alone. Casiano’s book is an essential building block of the still-evolving field of carceral history that will help its practitioners envision how to effectively take a wide, yet interconnected, view of policing in cities. The eventual efforts toward synthesis, which are sure to have a substantive impact on our broader understanding of the nation’s modern history, will owe much to pioneering case studies, including this one.