His brother, Fred, joined their mother in real estate development and management while still in his teens (Elizabeth Trump & Son).

During World War II, Trump switched from work on hospital X-ray machines to research into similar technologies, especially the development of radar.

As wartime shortages in Britain increased, many of its radar researchers would move to the well-funded laboratory at MIT, where they helped create groundbreaking progress in developing practical devices and systems, which would see widespread field deployment in combat.

[3] While Trump was not a businessman like his brother and nephew, he apparently shared their real estate expertise; Robinson said that land he persuaded HVE to purchase on Massachusetts Route 128 became as valuable as many years of the company's profits.

He researched using an electron beam from a high voltage accelerator as the deactivating agent in the treatment of municipal wastewater sludge.

[4] James Melcher, Trump's lab director, is quoted as saying: "John, over a period of three decades, would be approached by people of all sorts because he could make megavolt beams of ions and electrons – death rays... What did he do with it?

Cancer research, sterilizing sludge out in Deer Island [a waste disposal facility], all sorts of wondrous things.

"[17] Although Donald Trump has frequently claimed his uncle was the longest serving professor in the history of MIT, that is not correct.

He married Elora Sauerbrun (1913–1983), and they had three children: John Gordon Trump (1938–2012) of Watertown, Massachusetts; Christine Philp (1942–2021) of New London, New Hampshire; and Karen Ingraham of Los Alamos, New Mexico; and six grandchildren.