This dissertation consists of four micro-case studies of intersectional feminist college students' experiences with writing across digital extracurricular and academic domains. These micro-case studies were selected from a longitudinal study of eight students' experiences. In response to ongoing questions about writing knowledge transfer generally and transfer between online and academic contexts more specifically, this study was designed to explore whether and how these writers made connections between digital extracurricular and academic contexts of writing. Data collection consisted of four interviews with eight participants over the course of two years and the ongoing collection of academic and online writing samples over the course of one academic year. Through the analysis of interview data, I present two main types of learning transfer across domains; the first type of learning transfer is also supported by analysis of students' online writing. Through these micro-case studies, I shed light on two previously under-explored types of writing knowledge transfer across these domains, moving in both directions: the transfer (and transformation) of genre knowledge from academic contexts into digital extracurricular contexts, and the transfer of content knowledge forged through online reading into academic writing assignments. Participants in this study tended to confirm previous research suggesting that students generally compartmentalize their writing knowledge across these two domains. I illustrate this trend through a case study of a particularly salient example of such compartmentalization provided by the experiences of one participant, Nora. However, among the experiences of the four participants who served as focal cases for the analysis I present in this dissertation, there were two main exceptions to the compartmentalization trend. For example, in response to unprecedented online rhetorical situations, three participants in this study reported selecting and transforming prior academic genre knowledge by infusing it with multimodal elements to meet the demands of the new rhetorical situation. This cluster of findings suggests a previously unexplored relationship between antecedent genre uptake as articulated by Angela Rounsaville (2012), and what Kara Poe Alexander, Michael-John DePalma, and Jeffrey Ringer (2016) term "adaptive remediation," thus putting in conversation two previously separate theories of writing knowledge transfer. Additionally, when faced with open-ended writing assignments in unfamiliar disciplines in the humanities and social sciences, all participants reported drawing on their expertise in intersectional feminism, forged in the digital extracurriculum, as a means of locating topics for academic writing assignments. Through two micro-case studies of writers enacting this strategy, I explore the relationship between reading, content knowledge, and writing knowledge transfer, an area that is as yet under-explored in the writing knowledge transfer literature. Together, these two sets of findings suggest that in some cases undergraduate writers may transfer writing knowledge across online and academic domains, and that they can demonstrate considerable resourcefulness when doing so: when faced with an unprecedented, unfamiliar, or ill-defined rhetorical situation in one domain, four participants in this study drew on resources from another domain (e.g., academic genre knowledge; extracurricular content knowledge) in order to support their performance. These participants' experiences reinforce models of writing knowledge transfer that emphasize adaptation or transformation, and they also suggest that more sustained attention should be paid to the roles of digital extracurricular writing, multimodal composition, and reading in future transfer research. [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/en-US/products/dissertations/individuals.shtml.]