A post road is a road designated for the transportation of postal mail. In past centuries, only major towns had a post house and the roads used by post riders or mail coaches to carry mail among them were particularly important ones or, due to the special attention given them, became so. In various centuries and countries, post road became more or less equivalent to main road, royal road, or highway. The 20th century spread of postal service blurred the distinction.
In what was to later become the United States, post roads developed as the primary method of communicating information across and between the colonies. Post riders rode horses between towns, and milestones marked the distance between the major towns. Many of these milestones can still be found on highways such as the Boston Post Road. Until the advent of electronic communication beginning with the telegraph, post roads, using official mail and publications, private correspondence, and word of mouth, were the main means for the transfer of news and information in areas not served by seaports, navigable rivers or the overland canal system.
The Articles of Confederation authorized the national government to create post offices but not post roads. Adoption of the U.S. Constitution changed this, as Article I, Section Eight, known as the Postal Clause, specifically authorizes Congress the enumerated power "to establish post offices and post roads." This was generally interpreted liberally, to include all public highways. U.S. Supreme Court justice Joseph Story defended the broad interpretation that had become dominant in his influential Commentaries on the Constitution of the United States (1833). A law of 1838 designated all existing and future railroads as post roads.
Notable American post roads built for the purpose include:
- Albany Post Road, connects New York City to Albany, the capital of New York state
- Boston Post Road, traverses New England from New York to Boston
Notable Post Roads in Europe and Asia
- Great Post Road; (Dutch: De Grote Postweg), from Anyer to Panarukan, Indonesia, which was built during the governancy of Herman Willem Daendels of Dutch East Indies from 1808 to 1811.
- Dutch Post Road, (German: Niederländischer Postkurs) established in 1490, connected the Netherlands with coaching inns in Germany and Italy.
- Antwerp-Venice Post Road, similar to the Dutch Post Road.
- Bremen-Hamburg Post Road, approved by the king of Sweden on July 5, 1665 to establish regular mail service. A second route was routed from Cuxhaven through the Land of Wursten to Lehe.
- "Article 1, Section 8, Clause 7: Joseph Story, Commentaries on the Constitution 3:§§ 1119–42, 1144–45". Press-pubs.uchicago.edu. Retrieved 2008-10-28.