NRCS

USDA Natural Resource Conservation Service

Soil data

You can download data from their Web app (WSS, see below) and then (in theory) view it in their desktop app (if you have MS Access) or using their ArcGIS extension.

Workflow

1. Design areas of interest in ArcMap using shapefiles.
2. Create one AOI shapefile per county
3. Use the shapefiles to define AOI in the web app. WSS
4. Download the data
5. Load it into ArcMap using their extension