This dissertation studies the representation of custom in nineteenth-century Cuban proto-nationalist, anti-slavery novels along with Brazilian and U.S. novels of the same time period. I base my readings on Gómez de Avellaneda's Sab, Villaverde's Cecilia Valdés, Machado de Assis' Quincas Borba, and Hawthorne's The Scarlet Letter. Through these novels, I study how the representation of custom within these novels elucidates the relationship between aesthetics, politics, and ethics. Narratives of custom, particularly of Spanish American costumbrismo, comprise a literary genre that emerges from the rise of print culture and journalism in urban centers in the mid-eighteenth century and enters the novel shortly thereafter. Custom sketches or articles are short, thick in description of elements from social reality, and populated by character types (the dandy, the pedant, the intellectual, etc.), set scenes, and descriptions of local color. Drawn from social reality and often critiquing that reality, representations of custom present themselves as intrinsic to their social spaces, as traditional, and thus as always already historical. But, in fact, these representations are contemporaneous writings based on a mythic or imagined past. Though ostensibly custom sketches narrativize core practices or values proposed as originary, the historicity of the types and scenes of these sketches is rootless. Thus, these sketches narrate an imagined past in order to establish social values that tie or attempt to tie communities together in the present and into perpetuity.I study custom sketches and manners within 19th century novels as distinct novelistic discourses that enter into a dialogical relationship with the other narrative elements in the novel. This dialogical relationship is marked by a troubled coexistence, as these discourses are often in competition with one another. In Sab, the confrontations between custom and other novelistic discourses, namely romanticism, are used to expose a linkage between tradition and social decay. Gómez de Avellaneda suggests that ending slavery and mitigating patriarchy by appropriating tradition leads to no emancipation at all. In Cecilia Valdés, the encounters between custom and novelistic discourses demonstrate how custom can work in tandem with liberal politics to produce, paradoxically, a political project that seeks national independence by instantiating a liberal colonial order. Lastly, the interaction between custom and the novel, in Quincas Borba and The Scarlet Letter, uncovers how manners, the sphere of custom marked by description of social behavior as opposed to character types, mark subjects as aliens and as individuals. Though manners make possible and stabilize alienation, the quixotic and irreverent elements in Quincas Borba and The Scarlet Letter, respectively, are both the sources of alienation and of potential emancipation. Parallel to the potentiality constitutive of ethics, manners carry within themselves latent alternative notions of the good that may be potentially liberating. Altogether, these treatments of custom open to a double reading of repression and freedom and of liberal social critique and colonial power.