Definition
In American monetary law, the eagle was the gold coin of the United States with a face value of ten dollars. Authorized under the Coinage Act of 1792, the eagle served as the foundational unit of the U.S. gold coinage system, with related denominations defined in relation to it: the half eagle ($5), quarter eagle ($2.50), and double eagle ($20). The coin's metallic composition was fixed by statute at 258 grains of standard fineness, nine-tenths pure gold and one-tenth alloy of silver and copper. Gold eagle coinage was suspended for circulation by executive order in 1933 and the gold standard effectively abandoned, rendering the eagle a historical monetary denomination rather than a coin in active use.
Outside monetary law, eagle appears in American federal statutory law as the subject of significant wildlife protection legislation. The Bald and Golden Eagle Protection Act prohibits the taking, possession, sale, purchase, barter, transport, export, or import of bald eagles and golden eagles, their parts, nests, and eggs, with limited exceptions for scientific, religious, and tribal purposes.
Common Language
Modern common usage (Wiktionary): A large carnivorous bird in the family Accipitridae with a powerful hooked bill and keen vision; also a golf score of two under par for a hole; also a ten-dollar gold coin formerly used in the United States.
Historical common usage (Webster's 1913): Any large, rapacious bird of the Falcon family, especially of the genera Aquila and Haliaeetus, remarkable for strength, size, graceful figure, keenness of vision, and extraordinary flight.
The legal meaning of eagle is entirely distinct from its ornithological meaning in monetary contexts, but converges with the common meaning when the term appears in federal wildlife law. A researcher encountering eagle in an older commercial, probate, or debt instrument means the coin; a researcher encountering eagle in an environmental or criminal statute means the bird. Context determines which body of law applies entirely.
Recognized Forms
/SUBTYPES
As a monetary denomination, the eagle family included:
- Quarter Eagle: $2.50 gold coin
- Half Eagle: $5 gold coin
- Eagle: $10 gold coin
- Double Eagle: $20 gold coin
These denominations appear in historical contracts, estates, bond instruments, and currency regulations and are cross-referenced in monetary law sources under COIN.
Why It Matters in Research
Researchers face a genuine disambiguation problem with this term. In pre-1933 legal sources — contracts, wills, debt instruments, commercial pleadings — a reference to eagles almost certainly denotes the gold coin. Post-1933 legal sources mentioning eagles almost certainly concern wildlife protection. Mixing these research threads will produce confusion.
For monetary history research: the eagle's statutory specifications evolved across multiple Coinage Acts (1792, 1834, 1837, 1849, 1873), and the precise weight and fineness changed at several points. Bouvier's entry captures the composition applicable to its era, but a researcher working on disputes involving coins from different periods must verify which act governed at the relevant time. Anderson's Dictionary of Law redirects researchers to COIN, which is the correct landing point for deep monetary research.
For wildlife law research: the legal meaning of eagle in modern federal law is governed primarily by the Bald and Golden Eagle Protection Act (16 U.S.C. §§ 668–668d) and intersects with the Migratory Bird Treaty Act. The protections are broader than many researchers assume — extending beyond living birds to feathers, nests, and eggs — and the tribal religious exception has generated significant agency and appellate litigation. Researchers should not assume the common-law property framework applies to eagles or their parts; federal preemption is substantial.
For historical corpus research: sources from the late 19th and early 20th centuries may reference eagle in numismatic, contractual, or banking contexts without further specification. The double eagle ($20) is the denomination most likely to appear in large commercial transactions and estate inventories of that era.
Historical Dictionary Support
The historical dictionaries are in full agreement on the monetary definition: Black's (both editions), Bouvier's, and Rapalje & Lawrence all define eagle as the ten-dollar gold coin. Bouvier's is the most detailed, providing the precise grain weight and fineness formula — a useful primary reference for researchers needing the statutory specification as it stood in the mid-19th century. Anderson's Dictionary of Law redirects to COIN without independent definition, which is consistent with that dictionary's cross-referencing practice but unhelpful in isolation.
None of the historical legal dictionaries address eagle in the wildlife protection sense, which is expected: the Bald Eagle Protection Act was not enacted until 1940, well after the corpus of historical dictionaries was substantially complete. Researchers should not expect historical legal dictionaries to illuminate the modern statutory meaning.
The adjacency of EALDER, EALDERMAN, and EALDORMAN entries immediately following EAGLE in Black's and Rapalje & Lawrence reflects alphabetical proximity in the Saxon law vocabulary, not any substantive connection to the eagle entry.
Jurisdictional Note
The eagle as a monetary denomination was a creature of federal law and uniform across states. The wildlife protection framework under the Bald and Golden Eagle Protection Act is similarly federal, but enforcement intersects with state wildlife law in some contexts. Tribal nations have distinct rights regarding eagle feathers for religious use that operate outside the standard federal prohibition framework.
Encyclopedia Cross-Reference
Migratory Bird Treaty Act and the Bald and Golden Eagle Protection Act — Law Mind Environmental & Energy Law Encyclopedia