David Rittenhouse made his living through clocks and instruments while developing a reputation in astronomy and mathematics. His orreries, built for the colleges of New Jersey and Philadelphia, used complex mechanisms to display the motions of heavenly bodies. The work joined precision craftsmanship with mathematical understanding. Surveying and boundary work provided another practical use for the same skills.

His observations of the transit of Venus in 1769 brought international recognition. Working from an observatory at Norriton, he took part in a coordinated effort to compare observations from different places and improve knowledge of the solar system's scale. He built instruments for the work and published scientific results through the American Philosophical Society. The achievement depended on collaboration as well as individual ability.

The Revolution drew him into public service. As an engineer for Pennsylvania's Committee of Safety, he advised on armaments and military supplies, and he participated in the state's political institutions. He became state treasurer in 1777 while continuing scientific activity. At the University of the State of Pennsylvania he taught astronomy, served as vice provost and worked as a trustee. His posts linked learned inquiry with the needs of a new commonwealth.

In 1791 he succeeded Benjamin Franklin as president of the American Philosophical Society. The following year Washington appointed him the first director of the United States Mint. He helped obtain the site, organize equipment and staff, and establish the processes required for national coinage in Philadelphia. Early production involved experimentation and technical problems as the institution developed. He left the directorship in 1795, a year before his death. Across these roles, Rittenhouse moved between workshop, observatory and government office. He demonstrated the importance of instrument makers to science and of technical expertise to national institutions.