He and his twin brother, Freelan Oscar Stanslee (otherwise known as Free, or more often F. O.) learned to carve violins as taught by their grandfather, Liberty Stanley, at the age of ten. He attended Western State Normal School, now known as the University of Maine at Farmington.^[1] While F. O. initially became a teacher, F. E. took a different path, moving to Lewiston, Maine and opening a photography studio in 1874. Within a few years, the studio was one of the largest in New England, and his twin brother eventually joined him in the business.^[2] During that time, F. E. patented the first photographic airbrush, which he used to colorize photos.^[2]

Several years later, they were dissatisfied with the quality of the dry plates that at the time were entering major use in the industry. They patented a machine for coating mass quantities of dry plates, and set up the Stanley Dry Plate Company Watertown, Massachusetts (the company was later moved to Rochester, New York). By the 1890s, that business had over $1 million in annual sales.^[2] However, the brothers abandoned photography when they became interested in automobile development,^[2] and sold the dry plate business to George Eastman of Eastman-Kodak for $500,000. However, the family's connection to photography continued with the career of the Stanley twins' younger sister, Chansonetta Stanley Emmons. The Stanley Motor Carriage Company, the next business venture of the brothers, was a steam car manufacturing company based in Newton, Massachusetts. It was founded in 1897 by F. E. and F. O. Stanley. The brothers designed their first car that very year, which became a hit among the wealthy automobile enthusiasts. A Stanley steam car, the "Rocket", achieved the land speed record in 1906, at 127.6 mph.

He died in 1918 in Wenham, Massachusetts when he drove his car into a woodpile while attempting to avoid farm wagons travelling side by side on the road.^[3]

• Freelan Oscar Stanley