The environment became an important political issue due to publicity, increased awareness that the Earth's resources were finite and the desire to experience wilderness and parks
Membership of environmental organisations grew with middle-class liberals joining old organisations like the Sierra Club or new ones like The National Resource Defence Council
Environmentalism was strengthened by the revelation that the Love Canal near Niagara Falls was full of industrial waste that caused disproportionate numbers of miscarriages and birth defects in the local population which was relocated en masse in 1978