Founding-era dictionaries & original public meaning

When lawyers and judges argue about what the Constitution means, one recognized method is to ask: what did these words mean to an ordinary, informed reader at the time they were written and ratified? This is original public meaning (a form of originalism). A dictionary from the founding era is primary evidence of that meaning — which is the most powerful legitimate use of a dictionary in constitutional law.

The method, in one case

In District of Columbia v. Heller, 554 U.S. 570 (2008), the Court had to decide what the Second Amendment’s words meant. Justice Scalia’s majority opinion turned to founding-era dictionaries — among them Samuel Johnson’s Dictionary of the English Language (1755) and Noah Webster’s American Dictionary of the English Language (1828) — to establish the ordinary 18th-century meanings of “arms,” “keep,” and “bear.” The guiding principle: “The Constitution was written to be understood by the voters; its words and phrases were used in their normal and ordinary as distinguished from technical meaning.”

Use a founding-era dictionary to read a founding-era document. Reading 1787 words through a 2024 dictionary is how you get the meaning wrong. General principle, illustrated by Heller’s method.

Words whose meaning has shifted since 1787

These are concrete examples — each drawn from the lexicon, each sourced:

Commerce

Then vs. now: Founding-era usage centered on trade and exchange (and its transport), a narrower core than the sweeping modern reach; Gibbons v. Ogden, 22 U.S. (9 Wheat.) 1 (1824), gave it a broad early reading, and the scope has been contested ever since.

Sources: Gibbons v. Ogden, 22 U.S. 1 (1824) · Constitution Annotated — Commerce Clause

Domestic violence (constitutional sense)

Then vs. now: A clear example of meaning drift: at the Founding 'domestic violence' meant violence within the nation/state (as opposed to foreign invasion). The now-dominant meaning — abuse between household members — is a modern, statutory sense unrelated to Art. IV.

Sources: Constitution Annotated — Art. IV Guarantee Clause

Well regulated

Then vs. now: 'Regulate/regulated' in the 18th century commonly meant 'to make regular, orderly, or well-functioning' — distinct from the modern sense of imposing legal restrictions.

Sources: District of Columbia v. Heller, 554 U.S. 570 (2008)

Emolument

Then vs. now: Eighteenth-century dictionaries defined 'emolument' broadly as profit or advantage — a breadth central to modern Emoluments Clause litigation.

Sources: Constitution Annotated — Foreign Emoluments Clause

Where to get founding-era meaning

Samuel Johnson, A Dictionary of the English Language (1755) — the ordinary English of the era. see the directory →
Bouvier’s Law Dictionary (1839) — early American legal usage, adapted to U.S. law.
Contemporaneous sources: The Federalist & Anti-Federalist Papers, the ratification debates, and early statutes.

Caveat: founding-era meaning is evidence, argued and weighed — not an on/off switch. Different judges weigh it differently, and it is one method of interpretation among several.