Scholarly emphasis on the sea as a site of masculinizing labor and adventure has failed to recognize how women harnessed the liberatory affordances of maritime circulations for themselves. This dissertation addresses that oversight, analyzing how nineteenth-century North American women writers engaged oceanic histories of resistance to colonialism, ecological destruction, and racialized oppression. Focusing on the work of Nancy Prince, Frances Ellen Watkins Harper, Emily Dickinson, and E. Pauline Johnson, this project considers the waterborne conflicts and intimacies that formed along the United States’ northern border as well as its seacoasts. It moves from circum-Atlantic contexts to the Great Lakes—the so-called “sweetwater seas”—to establish women writers’ interest in a language of maritime trade, travel, and resistance, revealing how oceanic imaginaries circulated from ship and port into the home. These writers’ preoccupation with liminal—and littoral—zones of oceanic encounter constitutes an ecopolitical subjectivity I call the “terraqueous romantic.” This perspective controverts arguments that romanticism neglects the ecological complexity of the ocean in favor of an “anthropocentric” or “egotistical” sublime. The women I analyze do not turn to the sea to assert their mastery over nature but to confront the power of imperialism and environmental exploitation; their interest in oceanic metaphor, metonymy, and apostrophe suggests the sea’s erosive, destabilizing force in nineteenth-century discourses of race, gender, and nation. By identifying the ecocritical implications of this gendered preoccupation the sea, this dissertation more adequately historicizes theories of human-ocean relation, revealing the ongoing presence of women in oceanic contexts and literary histories from which they have long been excluded.