After suffering a disabling accident in 1873, he became a clerk for the Pennsylvania Railroad, and in 1885 became a curator at the transport section of the Smithsonian.
In 1900, his son John Elfreth Watkins Jr. (1875–?) contributed an article to the Ladies' Home Journal, entitled What May Happen in the Next Hundred Years. Watkins Jr.'s predictions were remarkably accurate for 1900.
"Photographs will be telegraphed from any distance. If there be a battle in China a hundred years hence, snapshots of its most striking events will be published in the newspapers an hour later... photographs will reproduce all of nature's colours."
Currently we have the Internet and color printers
"Americans will be taller by from one to two inches."
According to an article by the BBC, Watkins had unerring accuracy, the average American man in 1900 was about 66–67 inches (1.68–1.70m) tall and by 2000, the average was 69 inches (1.75m)
"Ready-cooked meals will be bought from establishment similar to our bakeries of today."
Ready cooked meals are a fixture in most supermarkets of today
"There will probably be from 350,000,000 to 500,000,000 people in America [implying the US plus Panama and Mexico]."
As of 2011 the US Census Bureau indicates that there are 311,000,000 Americans.
"Vegetables will be bathed in powerful electric light, serving, like sunlight, to hasten their growth. Electric currents applied to the soil will make valuable plants to grow larger and faster, and will kill troublesome weeds. Rays of coloured light will hasten the growth of many plants. Electricity applied to garden seeds will make them sprout and develop unusually early."
Electricity is commonly used now in greenhouses.
"Man will see around the world. Persons and things of all kinds will be brought within focus of cameras connected electrically with screens at opposite ends of circuits, thousands of miles at a span."
Internet and satellite television
"Huge forts on wheels will dash across open spaces at the speed of express trains of today."