The U.S. General Soil Map consists of general soil association units. It was developed by the National Cooperative Soil Survey and supersedes the State Soil Geographic (STATSGO) dataset published in 1994. It consists of a broad-based inventory of soils and non-soil areas that occur in a repeatable pattern on the landscape and that can be cartographically shown at the scale mapped. The dataset was created by generalizing more detailed soil survey maps. Where more detailed soil survey maps were not available, data on geology, topography, vegetation, and climate were assembled, together with Land Remote Sensing Satellite (LANDSAT) images. Soils of like areas were studied, and the probable classification and extent of the soils were determined.
The Google Earth version of this Soil Map provides the locations and names of the soils. Unfortunately, there does not seem to be an easy way to extract detailed soil characteristics for each soil type from the database created by NRCS. If you need the characteristics of the soil, you can search for the name of the soil at this website. If anyone knows of a better way to search for the soil characteristics, post a comment.
This is a very large dataset. The polygon data is several 100 megabytes. To get Google Earth to display the polygons on a national level, they have been split up into 1×1 degree tiles. There is also an Overview map. Simply zoom in and as you get close enough to the ground, the Overview map will automatically turn off and the detailed polygons will automatically turn on. Click on a polygon to see the name of the soil.