This web app displays data on vertical accretion rates and changes in elevation of salt marshes in the northeastern US (Connecticut, Maine, Massachusetts, New Hampshire, New York, and Rhode Island) as compiled from published studies and publicly available data sets. The vast majority of rates are reported as those determined by the original investigator, only converting rates to units of mm/yr for consistency. In a few cases where accretion rates were not originally defined but sufficient data were provided to determine rates of accretion, we calculated rates based on published chronological constraints and sediment core stratigraphies.