see my response to swatcoder in this thread. Most of the division came in the mid-to-late 60s. The early 60s was the calm before the storm.
Another example would be the ozone layer: When it became clear in the 70s that CFCs were destroying the ozone layer we were able to make changes to stop that from happening over the course of a decade. Can't imagine us being able to do something like that now.
I agree, now that "corporations are people" in the US it's hard to imagine being able to successfully battle them and force large-scale, cross-industry environmental-health measures to be taken. That is, unless it so happens that such measures maximize short-term profits in some way.