Abstract (from Wiley Online Library): Tidal marsh restoration and creation is growing in popularity due to the many and diverse set of services these important ecosystems provide. However, it is unclear what conditions within constructed settings will lead to the successful establishment of tidal marsh. Here we provide documentation for widespread and rapid development of tidal freshwater wetlands for a major urban estuary as an unintended result of early industrial development. Anthropogenic backwater areas established behind railroad berms, jetties, and dredge spoil islands resulted in the rapid accumulation of clastic material and the subsequent initiation of emergent marshes. In one case, historical aerial photos document this [...]