In 1956, honey bees of the African subspecies A. m. scutellata were imported to Brazil, and their descendents subsequently spread to South, Central, and North America. This invasion sparked significant academic controversy, particularly concerning the genetic composition of the expanding population. We review the biogeography and intraspecific phylogeny of Apis mellifera in the Old World as it pertains to African-derived bees in the Americas, the methods used to study gene flow between European-derived and African-derived populations in the New World, and the techniques used in identification of African-derived bees.