As the Endangered Species Act turns 50, those who first enforced it reflect on its mixed legacy

On Dec. 28, 1973, President Richard Nixon signed the Endangered Species Act. “Nothing,” he said, “is more priceless and more worthy of preservation than the rich array of animal life with which our country has been blessed.” The powerful new law charged the federal government with saving every endangered plant and animal in America and enjoyed nearly unanimous bipartisan support.

The Act was so sweeping that, in retrospect, it was bound to become controversial, especially since it allowed species to be listed as endangered without consideration for the economic consequences. In that way it pitted two American values against each other: the idea that Americans should preserve their incredible natural resources (the United States invented the national park, after all) and the notion that capitalism was king and private property inviolate.

The Endangered Species Act was just one in a raft of environmental legislation passed beginning in the mid-1960s that included the Clean Water Act, the Clean Air Act, the Wilderness Act and the National Wild and Scenic Rivers Act. Taken together, it was the most extensive environmental legislation the world had ever seen.

It was a time of widespread support for cleaning up the environment after unchecked greed had polluted our air and water and wiped out some of our most iconic species. Added to the desire for a cleaner natural world was a belief that the federal