Rough Crossings investigates the efforts of Willa Cather, F. Scott Fitzgerald, James Joyce, and Paul Muldoon to read and revise anti-imperial narratives from across the Atlantic. Drawing on transnational, modernist, and post-colonial studies, this dissertation features texts that are themselves bound up with texts from other national literary traditions. In other words, I look carefully at the ways in which these authors are themselves Atlantic readers. In their writing about empire and its local effects on their homelands, these writers find surprising ways to figure the material conditions of colonial contact at specific historical moments while bringing other times and other places to bear on their representations of those circumstances. While redrawing new spaces of belonging, the texts that compose my version of the Atlantic world also map a space imbued with experiences of loss: Ireland's decimated population after the Famine, housing crises for Catholics in Northern Ireland, the dispossession and removal of Native Americans from their lands, and the retreating national border of Mexico after the U.S.-Mexican War. Rather than being simply deferred until a later time, the dislocation of colonial trauma is worked out spatially in these authors' work. These stories take us to another place in addition to another time in order to witness and break out of the traumas of colonial and racial oppression. In substituting for or recovering from the forgotten, repressed, or dislocated blank spaces of traumatic experience, the texts at the heart of this dissertation begin to imagine new transatlantic revisions to the master narratives of empire. Building on the work of Irish Studies scholars like Seamus Deane and Luke Gibbons, and American Studies scholars like Shelley Streeby and Amy Kaplan, the readings I present in my dissertation offer an alternative view of the imperial thrust of American exceptionalism. Instead of viewing the West as the inevitable extension of America's growing empire, I figure the land beyond the frontier as an exceptional site of overlapping metropolitan and colonial spaces with crucial parallels to Ireland in the nineteenth and twentieth centuries. Rough Crossings thus brings regional literature into postcolonial discussions that have often struggled to find room for places like Cather's Prairie, Fitzgerald's Middle West, Bret Harte's California, and Muldoon's rural borderlands in Northern Ireland. This dissertation suggests that the contours of these contested spaces are best understood when seen from both sides of the Atlantic.