Definition
The postal service refers to the system of government-operated or government-regulated infrastructure through which written communications, parcels, and other mail are transmitted and delivered across jurisdictions. In American law, the term carries two related but distinct meanings:
1. The institutional framework. The organized federal system for mail handling, historically under the office of the Postmaster General and now administered by the United States Postal Service (USPS), an independent establishment of the executive branch created by the Postal Reorganization Act of 1970.
2. The regulatory and contractual regime. The body of law governing mail contracts, carrier obligations, postal rates, prohibited mailings, mail fraud, and the rights and liabilities arising from the transmission of correspondence and packages through official postal channels.
The postal service has always been a federal domain in the United States. Congress holds explicit constitutional authority to establish post offices and post roads, and federal statutes comprehensively govern what may be mailed, how contracts for mail carriage are awarded, and what remedies exist when mail is lost, delayed, or tampered with.
Common Language
Modern common usage (Wiktionary): A national or privatized organization responsible for the circulation and distribution of mail; used as a synonym for post office.
Historical common usage: No Webster's 1913 entry was provided for this term.
The common understanding of "postal service" as simply the organization that delivers mail understates the legal significance of the term. In legal research, postal service implicates a web of federal statutes governing procurement, contract rights, sovereign immunity, and criminal liability — none of which surfaces in the ordinary meaning of the phrase.
Why It Matters in Research
The structural transformation of 1970 is the single most important dividing line for postal service research. Before the Postal Reorganization Act of 1970, the Post Office Department was a cabinet-level agency; after 1970, the USPS became an independent establishment with its own litigation posture, labor relations framework, and quasi-commercial authority. Research in sources predating 1970 will reflect a different institutional entity with different rules for sovereign immunity, contract disputes, and tort liability. Do not assume pre-1970 authorities translate cleanly to modern USPS questions.
Mail contract procurement law deserves particular attention. Bouvier's notes the rule requiring advertisement and award to the lowest bidder, with limited modification thereafter — a principle with deep roots in federal procurement policy. Researchers tracing government contracting disputes in postal contexts should track how bid-and-award rules evolved through successive postal acts, as the specific statutory regime changed substantially across the nineteenth and twentieth centuries.
Mail fraud is a distinct and heavily litigated corpus. Federal mail fraud statutes (broadly, 18 U.S.C. § 1341 and its predecessors) have generated an enormous body of case law touching on wire fraud, RICO predicate acts, and the reach of federal jurisdiction. Researchers approaching fraud questions should not conflate the administrative postal service literature with the criminal law literature — they occupy different shelves entirely.
Sovereign immunity is a recurring trap. The USPS occupies an unusual position: it can sue and be sued, but not without limits. Pre-1970 postal tort claims were governed by general federal sovereign immunity rules; post-1970 claims arise under a specific statutory waiver. Researchers must identify which regime applies to the period in question.
Historical Dictionary Support
Bouvier's Law Dictionary treats postal service primarily as a procurement and contract matter, focusing on the Postmaster General's authority to advertise for mail transportation contracts and the requirement to award to the lowest bidder under the Act of July 26, 1892. Bouvier also flags the limited circumstances under which an awarded contract could subsequently be modified.
This framing reflects the dominant legal concern of the late nineteenth century: controlling patronage and corruption in mail contract awards, which had been a significant source of federal scandal. The "star route" frauds of the 1870s and 1880s — involving inflated contracts for mail delivery over rural routes — lent urgency to competitive bidding requirements that Bouvier's era took seriously.
What Bouvier's does not address is equally notable: the criminal dimension of postal law, the tort liability framework, labor relations, or the constitutional foundations of federal postal monopoly. Researchers relying solely on Bouvier's for postal service questions will find a narrow slice of the law as it existed at the turn of the twentieth century, with no guidance on the institutional transformation that followed.
Jurisdictional Note
Postal service law is exclusively federal in the United States. State law has no role in governing the transmission of mail or the contractual obligations of the USPS. However, state consumer protection law and state tort claims may become relevant in contexts where private mail carriers (UPS, FedEx) are involved, as those entities are not subject to the federal postal framework.