Recent research has established that African American Vernacular English (AAVE) is not monolithic. However, variation in AAVE has not been systematically described and mapped. This article uses new computational methods and social media to describe AAVE variation and to show AAVE dialect regions distinct from—and perpendicular to—the regions of other dialects of North American English. This study maps the geographic patterns of 30+ common nonstandard spellings on Twitter (e.g., sholl ‘sure’). It shows that nonstandard AAVE orthography delineates distinct dialect regions with shared phonological and lexical features. These regions are not coterminous with traditional North American dialect regions; rather, they align with patterns of movement during the Great Migrations.