The United States has, for the last generation, been going through a significant and highly contested period of change in its schools. A bipartisan consensus around a reform agenda of accountability and choice was rolled out nationwide, with promises of closing achievement gaps and raising standards, all without the infusion of new resources. This agenda accelerated during the Great Recession, with states cutting budgets and premiering new programs simultaneously. Meanwhile, teachers are now striking nationwide, and what was once treated as an inevitability has been exposed as political and open to change. One of the most significant epicenters of these educational transformations has been the Chicago Public Schools. This dissertation takes a close look at the political economy of neoliberal corporate education reform in Chicago from 1995 until 2015. Based on interviews with union activists, rank-and-file teachers, city officials, and representatives of business, as well as the analysis of school budget documents, city archives, legal proceedings, newspapers, union documents, and secondary sources, the dissertation is a case study of the fiscal and political origins of these changes, and the response of the Chicago Teacher Union to these dynamics. It addresses the puzzle of why an education reform strategy that increasingly pitted Democratic politicians against teachers and their unions, an important part of their base, developed in Chicago. It also addresses the puzzle of how the union, in an austerity period, managed to revitalize and go out on the militant 2012 strike. It begins with an argument about the role that the structural transformation of the city played in confronting politicians with new dilemmas in sustaining public education. Their responses, in light of the social terrain and changing political coalitions, led to their tying themselves more closely to business actors and distancing themselves from labor. This created a dilemma for an organized labor that had both grown more afraid of making use of its most important weapon, the strike, and had grown complacent in its relationship with political elites. As political actors became more committed to educational changes that internalized significant inequities and inadequacies in educational funding, teachers found themselves squeezed. The dissertation analyzes the various stages of these education reforms, culminating with the austerity mayoralty of Rahm Emanuel, and shows the basic logic that persists throughout the various initiatives. It also analyzes those reforms from above and below, offering testimony as to how those initiatives impacted life in the classroom. The dissertation then pivots to analyzing the response of the teachers' union to these conditions. The dissertation asks how the Chicago Teachers Union struck in 2012, after 25 years of quiescence, in such a militant, visible, and widely-supported labor action. It gains analytical leverage through the counterfactual comparison of the caucus that led the union through the strike--the Caucus of Rank and File Educators (CORE)--to a sister reform caucus Pro-Active Chicago Teachers (PACT). The latter also won power in a contested union election on a reform program, but neither led a strike, nor lasted more than a single term. The dissertation then proceeds to analyze the ratcheting-up effect of the Great Recession and how the teachers waged an unexpected defensive strike amidst austerity conditions, legal restrictions, and an unfavorable political climate. It ends by pointing out the significance and limits of the strike's achievements. Finally, the dissertation suggests avenues for future research into the politics of educational change, the influence of school finance, and the conditions that foster differential responses from politicians, business, teachers, unions, parents, and students. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]