1880
1900
1940
The most obvious change to me was Oklahoma, as we can see in the 60 years of these maps, more data was being collected. This can be verified because the data had become more split up to provide more accuracy. since 1880 it is known that the population in Midwestern states has grown significantly and as the population expanded so did the land use. These maps show an understandable display oof the cultivation od land use through 60 years.
Nicely done.