Definition
A drop letter is a piece of mail addressed for delivery within the same postal district in which it is deposited. In other words, both the sender and the recipient are located within the same local delivery area, and the letter never travels beyond that post office's jurisdiction. The term was used primarily in the context of nineteenth-century postal law and regulation to distinguish local mail from mail intended for transmission to a different district.
The practical significance of the designation was largely a matter of postal rates and liability. Drop letters were typically subject to a lower postage rate than mail requiring carriage between districts, and the handling obligations of postal officers differed accordingly.
Common Language
Modern common usage (Wiktionary): A letter mailed at a post office and either kept for general delivery or delivered to a post office box at that same post office. Also, in typography, a large decorative letter positioned below the baseline at the beginning of a block of text.
Historical common usage (Webster's 1913): Not separately defined; the term was understood in postal usage as a letter deposited at and delivered from the same post office.
The legal meaning of drop letter tracks the common postal meaning closely, but the legal context carries additional weight: the classification determined applicable postage rates, carrier duties, and, in cases of loss or misdelivery, the scope of any remedy available against postal authorities. The typographical meaning (a decorative initial letter) is wholly unrelated and should not cause confusion in legal research.
Why It Matters in Research
Researchers encounter drop letter most frequently in older postal law materials — federal postal regulations, congressional debates over postal rate structures, and treatises on government liability from the mid-to-late nineteenth century. The term fell out of active legal use as postal reorganization and rate simplification reduced the significance of local versus distant mail distinctions.
The key research trap is anachronism: drop letter is a period-specific term. Searching it in modern regulatory materials or contemporary postal law will return little or nothing. Its natural habitat is in sources predating the Postal Reorganization Act of 1970 and the creation of the United States Postal Service, when the Post Office Department operated under a more granular rate classification system that made the local/non-local distinction legally meaningful.
Researchers working on historical postal liability questions — for example, whether the federal government could be sued for a lost or misdirected drop letter under nineteenth-century sovereign immunity doctrine — will find the term scattered through lower federal court opinions and postal department circulars rather than in Supreme Court jurisprudence, where it rarely rose.
The term also appears in state court cases involving mail fraud, contractual delivery disputes, and the timeliness of legal notices sent by mail, where courts occasionally had to determine whether a communication qualified as a drop letter for rate or delivery purposes.
Historical Dictionary Support
Bouvier's defines drop letter simply and precisely: a letter addressed for delivery and mailed in the same district in which it is posted. The definition is functional rather than conceptual, which reflects how the term operated — as an administrative classification rather than a legal doctrine.
Bouvier's brevity here is appropriate. The term does not carry a body of common law behind it in the way that contract or tort terms do. Its legal significance was entirely derived from the postal statutes and regulations in force at any given time, which meant its content could change with each revision to the postal code. Researchers should not assume that a court's use of the term in 1870 carries identical meaning to its use in 1910.
No major divergence among historical sources has been identified. The term was used consistently in its postal-classification sense throughout the period in which it appeared in legal materials.
Jurisdictional Note
Drop letter is a term rooted in federal postal law. Because mail regulation is a federal function under the Postal Clause of the Constitution, the classification and its consequences were national rather than state-by-state. State law relevance arises only indirectly, where state courts applied the classification to resolve questions of notice, contract performance, or fraud.