Later in life he worked as a groundskeeper in a mobile home park where he resided, choosing to navigate town aboard a lawn mower rather than using a car.

In 1968 he received a Master of Arts degree from American International College in Springfield, Massachusetts, where his father worked as an English literature professor.

[2][1] Holt taught social studies and drivers' education at Thayer High School in Winchester, New Hampshire, before joining the Agway grain mill, where he eventually became a production manager.

[4] Post-mill closure, Holt engaged in various odd jobs around town and later worked as a groundskeeper at a mobile home park where he lived.

[6][7] Holt's financial success remained largely unknown to others because he continued to live frugally, relying on social security checks for sustenance in his final 15 years.

He died on June 6, 2023, naming Smith executor of his estate and bequeathing US$3.8 million to his town of Hinsdale to be used for health, education, culture or recreation.

[14] As of the end of November 2023, Hinsdale residents had been sharing ideas online about how to spend Holt's money, with the most popular suggestion being to reduce the tax base.