The beaver may not have the soaring majesty of the bald eagle (America’s national animal) or the stateliness of the bison (our national mammal, for now). But in his email to me, Goldfarb pointed out that the bald eagle depends in part on beaver-made habitats that support salmon and other fish. In addition, “as beavers raise water levels in ponds and wetlands, they kill surrounding trees and create ‘snags’—skeletal hunting perches from which eagles and other raptors scope their prey,” which, be honest, is very cool and frankly underrated work. Even our incumbent national mammal traditionally relied on beaver-controlled water supplies. “The Blackfeet and other Northern Plains tribes refused to kill” beavers, Goldfarb wrote to me, “largely because they recognized that beavers helped sustain the bison that they relied upon.”

Much as they sculpted the natural world that a growing nation would subsume, beavers—specifically, their valuable, hat-friendly fur—also helped shape the polities that became the United States. In his book, Goldfarb describes beaver furs, which Pilgrims used to repay their debts in England, as “the wind in the sails of the Mayflower” and quotes the historian James Truslow Adams: “The Bible and the beaver were the two mainstays of the young colony.” The acquisition of Manhattan (the “real prizes” were thousands of beaver skins, “the island itself was little more than a pot-sweetener”), the American Revolution, the Louisiana Purchase, the War of 1812—Goldfarb argues that more than “any other natural resource, beavers help explain just about every significant American geopolitical event between European arrival and the Civil War.”