In 1729, a horseback post ran from north of the Massachusetts Colony to Philadelphia. It took four weeks to send a letter from Boston to Williamsburg, Virginia. Improvements began in 1737, when Benjamin Franklin was appointed Deputy Postmaster General. In 1753, post service expanded to Charleston, South Carolina, and by 1757 had become a paying institution.
Franklin became Postmaster General in 1775. The painting shows him on a post office tour in a one-horse chaise, accompanied by his daughter on horseback, while a post rider delivers an urgent message.
The transition from post riders to mail stagecoaches occurred during and after the Revolutionary War. Levi Pease, a blacksmith, is credited with establishing the first successful stage line between Boston and New York.