The most dramatic change in the Illinois landscape since the start of its European phase is the fact that there are so many more people on it. Illinois' population exploded from a little more than 800,000 in 1850 to well over eight million a century later. Census numbers alone are not a dependable measure of the stress that human populations put on natural systems. Relative wealth matters. Total solid waste output in Illinois has outpaced recent population growth.
Technology matters as well.
But the 1930 rural population had an impact on the land that was disproportionate to its size. The result was the elimination of the secondary grasslands ecology that had replaced the original prairie as the dominant system in rural Illinois. Coal was known to exist in Illinois as early as the 17th century, but it was not until trees grew scarce that coal commanded prices high enough to return the higher costs of mining and shipping it. Similarly, lower-priced alternatives can deplete the economic potential of resources that remain physically intact. Decisions about resource use usually depend on the prices resources can command.