Sulfur dioxide (SO₂), a criteria pollutant, and sulfate (SO₄^2-) deposition are major environmental concerns and both have been on the decline in the Eastern U.S. for more than two decades. We combined satellite column SO₂ data from the Ozone Monitoring Instrument (OMI), and SO₄^2- wet deposition data from the NADP (National Atmospheric Deposition Program) to investigate the temporal and spatial relationship between the downward trends in SO₂ emissions and sulfate deposition over the eastern U.S. from 2005 to 2015. To establish a relationship between SO₂ emission sources and receptor sites, we conducted a Potential Source Contribution Function (PSCF) analysis based on HYSPLIT back trajectories for five selected Air Quality System (AQS) sites - (Hackney, OH, Akron, OH, South Fayette, PA, Wilmington, DE, and Beltsville, MD). Back trajectories were run for three summers (JJA) and three winters (DJF) and used to generate seasonal climatology PSCFs for each site. The OMI SO₂ and interpolated NADP sulfate deposition trends were normalized and overlapped with the PSCF, to identify the areas that had the highest contribution to the observed deposition trend. The results suggest that emission reductions along the Ohio River Valley have led to decreases in sulfate deposition at Hackney, Akron and South Fayette. Emission reductions in southeast PA have resulted in improvements in sulfate deposition at Wilmington, DE, while for Beltsville, reductions from both the Ohio River Valley and nearby have had an impact on sulfate deposition. For Beltsville, sources closer than 300 km from the site contribute roughly 56% and 82% of the observed deposition trends in winter and summer respectively, reflecting seasonal changes in transport pattern as well as faster SO₂ oxidation in summer. The results also suggest that emissions and deposition are linked through not only the location of sources relative to the observing sites, but also the weather patterns characteristic to the region, as evidenced by differences in winter and summer contributions. The methodology developed in this study is applicable to other regions with significant trends and can be used to estimate the potential benefits of emission reduction in those areas.