Public libraries, important spaces for accessing assistance and resources, are increasingly focusing on Science, Technology, Engineering, Arts, and Mathematics (STEAM) and hands-on learning (Lee & Phillips, 2019). While they are promising spaces for STEAM learning that supports marginalized communities and multi-generational engagement, this potential is threatened by policies and practices shaped by values based in white supremacy, classism, heteronormativity, and ableism. Additionally, library staff face a number of challenges to implementing social innovations in libraries, including a lack of professional development and adequate funding.In my dissertation, I studied the following research questions: (1) How do public libraries engage (or fail to engage) diverse members of their communities in meaningful and consequential learning through STEAM programs and resources? (2) How do infrastructures and the values held by library staff and patrons impact the experiences and access of different types of patrons interfacing with the library? To answer my research questions, I used an interpretive multiple-case study design to engage in holistic study of two geographically, racially, and socioeconomically diverse public libraries in the U.S. that were making efforts to more equitably engage historically marginalized communities through STEAM programs. I utilized interdisciplinary concepts of infrastructures and interfacing to examine when and how power relations embedded in infrastructures are present in activity in public libraries.I name material, policy & procedure, social, and communication infrastructures as being significant to public library contexts. I then describe how these infrastructures, along with the values held by library staff and participants shaped access to meaningful and consequential learning opportunities for different types of patrons, and the ways these varied infrastructures led to inequity. My findings highlight the importance of social infrastructure in particular in bolstering access to meaningful and consequential STEAM learning in public libraries. Across both cases, library staff, particularly library staff of color, encountered a number of challenges to facilitating meaningful and consequential learning, which were related to both material and policy infrastructures. They developed strategies to work around systems to accomplish values aligned liberatory goals in their work, seeding possibilities for consequential learning from their own values and lived experiences. These cases offer insight to both researchers and practitioners who are looking to design and implement meaningful and consequential STEAM learning in public library settings. I suggest several design considerations for facilitating equitable meaningful and consequential STEAM learning, including centering transformative relations within the walls of the library and in the local community more broadly, rather than a more typical equity diversity and inclusion approach. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]