Sixteen Acer rubrum (red maple)-dominated wetlands in three hydrogeomorphic settings (depressional, riverine, seepage slope) were sampled in southeastern Massachusetts. Quantitative data of vegetation from five strata were compared with soil-chemistry measurements using detrended correspondence analysis (DCA) to determine if hydrogeomorphic (HGM) setting was related to species composition. Although all sampled wetlands were dominated or co-dominated by red maple, DCA-differentiated stands according to HGM setting, i.e., riverine flood-plain wetlands separated from depressional (kettle) wetlands and slope wetlands on the DCA ordination. Further, species richness was lowest in depressional wetlands and highest in riverine wetlands, reflecting differences in soil chemistry and soil type, ultimately determined by hydrogeomorphic setting. Depressional swamps overwhelmingly dominated by red maple and those with Chamaecyparis thyoides (Atlantic white cedar [AWC]) were very similar in understory composition, soil chemistry and type, and ordination position, suggesting that many of the red maple depressions were probably once AWC swamps. Post-colonial forest-management practices such as repeated cutting of stands, fire suppression, draining for conversion to cranberry bog, and subsequent abandonment have degraded and fragmented AWC swamps throughout southeastern Massachusetts and extensively reduced their areal extent. However, recent abandonments of cranberry bogs have provided opportunities for restoring AWC wetlands to a portion of their original habitat.