If a plant's management decided to relocate, it would be catastrophic to the local economy. So there was not much public support for our early efforts. Public support only began to explode in the late 1960s. It led to the creation of EPA, which never would have been established had it not been for public demand. That I am absolutely certain of.
Public opinion remains absolutely essential for anything to be done on behalf of the environment.
Absent that, nothing will happen because the forces of the economy and the impact on people's livelihood are so much more automatic and endemic. Absent some countervailing public pressure for the environment, nothing much will happen. But I do think you've got to have public support for environmental protection or it won't happen. That's what shifted between the early 1960s and the time EPA was formed. The federal role was fairly peripheral.