Sediment samples, including marsh and estuarine surface samples and marsh push and peat-auger cores, were collected from Point aux Chenes, Mississippi from October 23-26, 2018, and August 4, 2021. Marsh surface samples (top 1 centimeter (cm) of sediment; sample names appended with S), marsh push cores (core names appended with M) and peat-auger cores (core names appended with R) were collected along 50-meter (m), shore perpendicular, transects identified as sites 5, 6, 7, and 9. All samples in the dataset are referred to by alternate field activity number (FAN) 18CCT09 (FAN 2018-358-FA) and alternate FAN 21CCT02 (FAN 2021-320-FA). Estuarine PONAR grab samples (sample names appended with G), marsh surface samples, and push cores were collected and brought back for sedimentological analyses including dry bulk density, organic content, grain-size for the development of a sedimentological baseline, and gamma spectroscopy for the development of geochronologies. Peat augers were collected, described for depth to peat, and discarded in the field. Marsh and estuarine surface and core sediment samples are part of the U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center's (SPCMSC) Estuarine-MaRsh Geology (EMRG) and Sea-level and Storms Impacts on Estuarine Environments and Shorelines (SSIEES) research projects which study how and where short- and long-term marsh and estuarine coastal process interact in order to identify and evaluate geologic and geomorphic variables influences on marshes and their resiliency under different storm and sea-level scenarios, determine marsh-upland boundary change rates, and sediment accumulation and erosion rates. Note: This data release was revised on August 2, 2021, and versioned on August 23, 2023. Please see the Suggested Citation section on the data release webpage for more details.