 These photos were commissioned by the Environmental Protection Agency in the early 70s to document pollution in the US. They show how dire the situation was before environmental protections were put in place. Now they remind us of why we need those protections. Today, the future of the EPA is uncertain. President Trump is expected to slash the EPA's budget. The head of the EPA, Scott Pruitt, wants to roll back many of the regulations that empowered the agency. And a very short bill in Congress calls for terminating the EPA by the end of 2018. Literally, this is all it is. But most Americans aren't really on board. A recent poll showed that more than 60% of Americans, including Republicans, want the EPA's powers to be preserved or strengthened under Trump. There is tremendous public support for clean air and clean water and the basic mission of the agency is tremendously popular and people are counting on the government to provide those protections. The EPA was created in 1970 by Republican President Richard Nixon, and there was broad bipartisan support for it. Restoring nature to its natural state is a cause beyond party and beyond factions. It has become a common cause of all the people of this country. That's because back then many Americans could see pollution firsthand. Most US cities were engulfed in smog. Los Angeles was named the smog capital of the world. In 1948, in the small town of Donora, Pennsylvania, toxic smog produced by the local zinc plant and steel mill killed 20 people. Many others got sick. In 1969, a layer of oil and debris floating on the Cuyahoga River in Cleveland was accidentally set on fire. Though Cuyahoga is the most famous, burning rivers across the US were not an unusual sight back then. The EPA and the laws the agency enforces helped change all that. Now we breathe cleaner air. From 1970 to 2015, natural emissions of pollutants like lead, carbon monoxide and nitrogen dioxide have declined by an average of 70%. Cleaner air means that 160,000 people in the US didn't die prematurely due to pollution in 2010 alone. But deaths aren't all of it. 86,000 emergency room visits and 13 million lost days from work were also prevented. That's good for human health and for the economy. Since the 1980s, the EPA has also worked with local authorities to clean up some of the most polluted sites in the US, from radioactive waste to illegal waste dumps. You know, I think overall it's been an incredibly important agency and I think the way the environment has improved since 1970, it's hard as a historian to do counterfactual. Where would we be without the EPA? But I think the EPA has played a central role in affecting those improvements. In his first speech to the EPA, Prude said that he wishes to give responsibility for environmental protection back to the states. But here's the rub. Pollution doesn't respect state boundaries. Just think about acid rain. Acid rain was creating a lot of damage in the forest in the Northeastern US, even though the pollution was coming from Midwestern states like Ohio, Illinois and Michigan. So by setting national standards, the EPA can make sure that one state's loser regulations don't hurt another state nearby. Today, environmental challenges aren't as obvious as those of the 60s and 70s, but they're still present. Climate change will pose new threats like rising sea levels, heat waves and more destructive natural disasters. We're in the middle of a mass extinction, and lead in drinking water is a problem that still affects millions of Americans across the US. The environmental degradation recorded by the EPA's photos in the 1970s wasn't so long ago. We often take clean air and water for granted, but we have clean air and water because of agencies like the EPA.