Approximately 2100 km of high-resolution seismic data from the Alabama/Florida shelf were interpreted to investigate the origin of a thick ( approximately 30 m) late Pleistocene shelf-perched seismic unit. In contrast to previous sequence stratigraphic studies, the eastern Alabama/northwest Florida study area is characterized by small coastal plain drainage systems, a narrow continental shelf, and very low subsidence rates. Moreover, the area of interest is beyond the influence of salt tectonics and growth faulting. Within a sequence stratigraphic framework, this shelf-perched unit has the appearance of a backstepped, drowned transgressive systems tract. However, seismic stratigraphic correlation indicates that locally the unit completely prograded the margin. Within our scenario, the majority of the shelf-perched unit is not transgressive, but rather part of the late highstand systems tract. Based on available age control, late-stage shelf-margin progradation is inferred to have occurred in the latest highstand of the last eustatic cycle (i.e. oxygen-isotope stage 2) when fluvial systems coalesced across the emergent coastal plain. The late Pleistocene transgressive systems tract was probably sourced by transgressive ravinement. Coastal plain sediment supply provided little new localized input during baselevel rise. The transgressive systems tract is therefore exceedingly thin with regional distribution.