So far, we have considered the founders as leaders in a time of change, and then as technologists in their own right. This, the third article in the series, is about the city where their technical work took root.

In September this year, when C-level technology executives gather in Philadelphia for The CIO Initiative® Summit, they will be in the city that was the working capital of American technical life. The decades surrounding the Revolution were a technical revolution as much as a political one, and that revolution had a center. The center was right here in Philadelphia.

Why Here?

By the 1770s, Philadelphia was the largest city in the colonies, with roughly forty thousand residents. It was the busiest port north of the Caribbean, the printing capital of British North America, and the seat of more learned activity than any other colonial city. None of this was accidental.

Three things shaped Philadelphia into what it became.

The Quaker tradition. William Penn’s colony was founded on principles that placed unusual value on practical knowledge, useful work, and the dignity of trades. A skilled craftsman in Philadelphia was respected in ways he might not have been in Boston or Charleston. The instrument maker, the printer, the clockmaker, and the surveyor were not adjacent to the city’s intellectual life. They were part of it.

The port. Philadelphia sat at the head of navigation on the Delaware River, with deep water access to the Atlantic and roads connecting it to inland markets. Goods flowed in. Books, scientific instruments, and printed matter from Europe arrived here first. Ideas traveled with them. A natural philosopher in Philadelphia in 1770 had access to the latest European thinking faster than counterparts in any other American city.

Critical mass. The combination of cultural respect for technical work and commercial advantages attracted skilled craftsmen and curious minds. Over time, that critical mass became something more. Practitioners who might have worked in isolation elsewhere worked alongside each other in Philadelphia. They corresponded, collaborated, competed, and improved each other’s work. Cities have a way of becoming what their inhabitants are doing, and what Philadelphia’s inhabitants were doing, by the 1770s, was thinking carefully about how the natural world worked and how it could be put to use.

A City of Practical Inquiry

Walk the streets of Philadelphia in 1775, and you would have passed a remarkable density of technical work in progress.

On Market Street, Franklin’s print shop had grown into one of the largest in the colonies, and behind it sat the headquarters of his colonial postal system. The American Philosophical Society had a regular meeting calendar. The Library Company offered shared access to a collection of books which no average individual could afford on their own. The Pennsylvania Hospital, founded in 1751, was treating patients and conducting medical observation as an integrated practice. The College of Philadelphia, now the University of Pennsylvania, was training students in natural philosophy, medicine, and practical arts.

In smaller shops scattered around the city, instrument makers were building telescopes, microscopes, surveying compasses, and clocks. Glaziers like Thomas Godfrey were grinding lenses and inventing optical instruments. Clockmakers were producing precision mechanisms. Naturalists like John Bartram, working from his garden on the Schuylkill River, were cataloging the plants of North America and sending specimens to correspondents across Europe. Bartram’s son William would later produce one of the most influential works of natural history written in the early Republic.

Medical research in that time was centered here too. Doctors like Benjamin Rush, who would later sign the Declaration of Independence, were practicing in Philadelphia and engaging in the kind of clinical observation that was slowly turning medicine from craft into science. Rush would go on to be one of the most prominent physicians of his generation.

None of this was happening in isolation. The instrument makers supplied the natural philosophers. The natural philosophers shared their findings with the physicians. The physicians turned to the printers when they had something to publish. The printers in turn distributed the work across the colonies through Franklin’s postal network. The city worked because the parts worked together.

Rittenhouse as the Anchor

If one person embodied Philadelphia’s technical revolution, it was David Rittenhouse.

David Rittenhouse was born in 1732 on a farm just outside the city. He was largely self-taught, and by his early twenties he had built a clockmaking practice that rivaled any in the colonies. He soon moved on to producing more ambitious instruments. His orreries, mechanical models of the solar system, were amongst the most significant scientific instruments built in America in the eighteenth century. Thomas Jefferson, writing in his Notes on the State of Virginia, called him “second to no astronomer living.”

In 1769, Rittenhouse led the colonial observation of the Transit of Venus from a temporary observatory in Norriton, just outside Philadelphia. The Transit was a globally coordinated scientific event, with observers stationed across the world to measure the precise moment Venus crossed the face of the Sun. The combined data made it possible to calculate the distance from Earth to the Sun with new precision. Rittenhouse’s measurements were among the most accurate recorded.

During the Revolution he served as Pennsylvania’s State Treasurer and as Vice President of the state’s Council of Safety. After the war he succeeded Franklin as President of the American Philosophical Society. In 1792, George Washington appointed him the first Director of the United States Mint.

Rittenhouse never left the Philadelphia area for any extended period. The square that bears his name in Center City is roughly a fifteen-minute walk from where the CIO Initiative® Summit will gather this September. It was named for him in 1825, decades after his death, because Philadelphia still remembered what he had been to the city.

Reach Beyond the City

The technical energy that gathered in Philadelphia did not stay there. It flowed outward through the city’s networks.

Benjamin Banneker is a clear example. Banneker was a free Black mathematician and astronomer who lived his entire life on his family’s farm in Baltimore County, Maryland. He was largely self-taught. He produced astronomical almanacs from 1792 forward and helped survey the boundaries of the District of Columbia. His work reached the public because the Pennsylvania Abolition Society, whose first president had been Franklin himself, supported the publication and distribution of his almanacs. Banneker was not a Philadelphian, but his work entered the wider world through Philadelphia’s networks.

The same pattern repeated across the early Republic. Surveys, instruments, almanacs, treatises, and trained practitioners moved out of Philadelphia and into other cities. When Washington appointed Rittenhouse the first Director of the Mint, he was choosing a Philadelphian for what was then a Philadelphia institution. When Benjamin Rush trained the next generation of physicians, those physicians dispersed across the new country. The city exported people and ideas, and the country was shaped by what it received.

What This Means

Place matters in technology, and it always has.

Modern technology leaders sometimes treat geography as incidental. The cloud is everywhere. The team is distributed. The work is location-independent. There is real truth in this, and there is also a quiet half-truth. The cities and the institutions that develop critical mass in any given era shape what gets built. Silicon Valley is the most obvious modern example. Boston, Austin, Tel Aviv, Bangalore, and Shenzhen each carry their own version of the dynamic. People who can work anywhere still choose where to be, and the places they choose compound. Philadelphia was that kind of place in the 1770s.

This is worth remembering as a technology leader chooses where to invest, where to recruit, where to build, and where to convene. Place is not the only variable that matters, but it is rarely incidental.

A Closing Thought

The CIO Initiative® Summit convenes this year in Philadelphia not just because Philadelphia is a convenient airport hub, but because Philadelphia is what it is. A short walk from the Notary Hotel, where the Summit is to be held, will take you past Independence Hall, past the building that houses the American Philosophical Society, past Carpenters’ Hall, past the site of Franklin’s print shop, and ultimately to Rittenhouse Square. It is a walk through the working capital of an earlier technical revolution.

The work being done in 2026 is not the same as the work being done in 1776. Yet the disciplines, the habits, and the impulse to build something durable in uncertain conditions are recognizable across centuries. Philadelphia is a useful place to remember that.