Terrestrial soil is a large reservoir of atmospherically deposited mercury (Hg). However, few studies have evaluated the accumulation of Hg in terrestrial ecosystems in the northeastern United States, a region which is sensitive to atmospheric Hg deposition. In this study, we characterize Hg and organic matter in soil profiles from 139 sampling sites for five sub-regions across the northeastern United States, and estimate atmospheric Hg deposition to these sites by combining numerical modeling with experimental data from the literature. We did not observe any significant relationships between current net atmospheric Hg deposition and soil Hg concentrations or pools, even though soils are a net sink for Hg inputs. Soil Hg appears to be preserved relative to organic carbon (OC) and/or nitrogen (N) in the soil matrix, as a significant negative relationship was observed between the ratios of Hg/OC and OC/N (r = 0.54, p < 0.0001) that shapes the horizonal distribution patterns. We estimated that atmospheric Hg deposition since 1850 (3.97 mg m-2) accounts for 102% of the Hg pool in the organic horizons (3.88 mg m-2) and 19% of the total soil Hg pool (21.32 mg m-2), except for the Southern New England (SNE) sub-region. The mean residence time for soil Hg was estimated to be 1,800 years, except SNE which was 800 years. These patterns suggest that in additional to atmospheric deposition, the accumulation of soil Hg is linked to the mineral diagenetic and soil development processes in the region.