In the 1870s and 1880s, Russian soil scientists under Vasilii Dokuchaev devised an innovative science of soils. They understood soils as natural-historical bodies that had formed in the environments in which they existed. The innovation, which was based on field work in the steppes, allowed the mapping of large soil groups over extensive areas. It could be applied around the world and suggested that the soils of the Great Plains were similar to those of the steppes. The US government soil survey that began in 1899 under the direction of Milton Whitney was largely limited to a physical and geological understanding of soils. Whitney was hostile to the Russian innovation and tried to prevent its spread among American scientists.