Joshua Humphrey

Upper Darby, PA · est. 1985

Built around 1684, Sellers Hall was the first permanent home in Upper Darby, raised by Samuel Sellers and his bride Anna Gibbons in the earliest days of Penn's colony. The family became famous for its bent toward mechanics and science across generations. One son, John Sellers, helped found the American Philosophical Society and in 1769 joined the celebrated observation of Venus crossing the face of the sun.

Clifton Heights, PA · est. 2019

A coiled steel spring that could "walk" down stairs became one of the twentieth century's most beloved toys — and it was made right here. Richard James stumbled onto the idea in 1943, his wife Betty gave it the name Slinky, and James Industries manufactured it in Clifton Heights for decades. When Richard walked away in 1960 and left a nearly bankrupt firm to Betty, she rebuilt it into a multimillion-dollar enterprise, later earning a place in the Toy Industry Hall of Fame.

Philadelphia, PA · est. 2006

At 3747 Ridge Avenue in Philadelphia, the computer age turned commercial. Here BINAC passed its verification tests in 1949 as the world's first commercial, electronic, stored-program digital computer, followed in 1951 by the customer acceptance of UNIVAC I. Both machines were led by J. Presper Eckert and John W. Mauchly, the same duo who had built the pioneering ENIAC.

Philadelphia, PA · est. 1991

In 1690 William Rittenhouse, the first Mennonite minister in America, built the English colonies' first paper mill along the Wissahickon Creek. Generations of his family expanded the operation, turning this valley into the birthplace of American papermaking. By the 1850s the village had grown to more than forty buildings, seven of which still survive from this once-thriving industrial hamlet. It was also the birthplace, in 1732, of the noted astronomer and instrument-maker David Rittenhouse.