The peak of environmental legislation in the U.S. occurred in the 1960s and 1970s. In the 1970s in particular, the U.S. Congress passed a number of important laws to repair environmental damage and protect the environment from further pollution. In fact, the relatively clean and healthy environment you enjoy today is a result of the laws passed during this period (some of which have been updated multiple times since their initial passing).
Here are a few of the laws that continue to have a big impact today:
Clean Air Act of 1970: This law was the first to regulate air pollution on a national scale and set goals for improving air quality across the U.S. It was updated in 1990 to address ozone depletion and acid rain, in addition to overall air quality.
Clean Water Act of 1972: Before this law, no rules mandated what type or amount of waste could be dumped into public waters. The Clean Water Act is viewed as one of the most successful pieces of environmental legislation because it led to dramatic improvement in water quality across the U.S.
Endangered Species Act of 1973: The Endangered Species Act set up a process for legally recognizing and seeking to conserve plant and animal species in danger of extinction. As a result of this law, many species have recovered from near extinction, including the bald eagle, whooping crane, and grey wolf.
Safe Drinking Water Act of 1974: This piece of legislation was aimed at improving public health by protecting public drinking water supplies from contamination. Amendments in 1986 and 1996 shifted the focus away from treating polluted water to protecting drinking water from pollution at its source.
National Forest Management Act of 1976: This law required that national forest resources be managed through an approach that considers how timber removal affects the ecosystem as a whole. One effect of this act is that forest management plans also evaluate non-timber land use (such as recreation).