Definition
A pre-Revolutionary French monetary unit that appeared in early American federal law as a defined valuation for customs purposes. The livre tournois was the principal unit of account in France for several centuries before the Revolution, originating at Tours and eventually supplanting the livre parisis as the standard French currency of reckoning. It was not a coin with fixed metallic content in later periods so much as a unit of account — a denomination used to price goods and settle obligations — though coins denominated in livres were struck at various times.
In American legal context, the term appears primarily in federal customs statutes. Congress, needing a fixed domestic equivalent for duties assessed on French goods, assigned the livre tournois a statutory value of eighteen and one-half cents by Act of March 2, 1799 (commonly cited as the Act of March 2, 1798, § 61; 1 Story, Laws, 629). This statutory conversion rate gave the term its legal significance: it told customs officers and importers at what dollar equivalent French prices denominated in livres should be calculated when determining ad valorem duties.
Common Language
Modern common usage (Wiktionary): One of numerous currencies used in France in the Middle Ages; alternatively, a unit of account used in France in the Middle Ages and the early modern period.
Historical common usage: The term does not appear as a distinct entry in Webster's 1913, reflecting its status as a foreign-language term that had largely passed from active use in American commerce by the late nineteenth century.
Editorial note: The common historical usage emphasizes the livre tournois as a medieval monetary instrument, but its legal significance in American sources is narrower and more recent: a statutory conversion rate applied to French import valuations in the early federal period. Researchers encountering the term in legal sources should look not for monetary history but for customs valuation doctrine.
Why It Matters in Research
This term is almost exclusively encountered in early federal customs law and in contracts, invoices, or commercial correspondence predating the Napoleonic monetary reforms that replaced the livre with the franc (1795–1803). Researchers working with pre-1800 American trade records, import disputes, or tariff litigation will find the livre tournois appearing as the denominating currency of French goods on manifests and bills of lading.
The critical research trap is anachronism: the statutory valuation of eighteen and a half cents was fixed by federal law for customs computation purposes and does not reflect any general or market exchange rate. Using the statutory rate to interpret private contracts denominated in livres — or to perform historical currency conversions outside the customs context — would be methodologically unsound.
Corpus connections: References to the livre tournois in legal sources almost always occur alongside or immediately adjacent to tables of foreign coin valuations issued by Treasury or enacted by Congress. Bouvier's cross-reference to FOREIGN COINS is the natural companion entry. Researchers should also consult early Story compilations of U.S. statutes, where the foreign coin valuation schedules appear in full context.
The term essentially disappears from American legal sources after the early nineteenth century, when France's adoption of the franc and the regularization of U.S. customs administration rendered the old valuation schedules obsolete. Its presence in a document is therefore itself a dating signal.
Historical Dictionary Support
Black's (1st ed.), Black's (2nd ed.), and Bouvier's are in complete agreement: all three define the livre tournois by reference to the same statute and the same valuation of eighteen and a half cents. The convergence is not surprising — all three likely drew from Story's compilation directly or from a common secondary source. No divergence in legal definition appears across these dictionaries.
What the historical dictionaries do not address is the monetary history underlying the term: the distinction between the livre tournois as a unit of account versus as a struck coin, the relationship between the livre tournois and the livre parisis, or the political and fiscal history that made French currency so variable in the centuries before the Revolution. For those questions, legal dictionary sources are not adequate, and researchers must turn to monetary history literature.
Bouvier's cross-reference to FOREIGN COINS is the most useful navigational signal in the historical sources, pointing researchers toward the broader statutory framework of which this entry is one part.
Jurisdictional Note
The eighteen-and-a-half-cent valuation was a federal statutory figure governing import duties and has no state law analog. State courts encountering livre-denominated contracts would have applied general principles of foreign currency conversion, not the customs rate.