The Bird of Washington Falco washingtoniiAudubon, 1827, was a new species of eagle published in the opening plates of John James Audubon's influential work, The birds of America (1827–38). It was the first plate engraved by Robert Havell Jr. and the first new species Audubon described in his career. However, the Bird of Washington was published without specimen evidence and, to this day, no specimen with the anatomical characters in Audubon's descriptions and plate has ever been found. To shed light on the case, I conducted an exhaustive search for primary (non-print) sources in multiple archives in the USA and transcripts in the literature. Here, I demonstrate beyond reasonable doubt that Audubon's painting of the Bird of Washington was not ‘faithfully figured from a fresh-killed specimen’, as he claimed, but was the product of both plagiarism and invention. The preponderance of evidence suggests that the Bird of Washington was an elaborate lie that Audubon concocted to convince members of the English nobility who were sympathetic to American affairs, to subscribe to and promote his work. Audubon rode his Bird of Washington to widespread fame and then actively maintained the ruse for more than 20 years, until his death, fuelling decades of confusion among scientists and the general public. The broad implications for Audubon-related scholarship and ornithology are discussed.