What position did president john adams describe as being "the most insignificant office that was the invention of man ... or his imagination conceived"?

This position was that of a Vice President

Explanation:

John Adams was one of the founding fathers of the United States and played a crucial role in the development of the country.

Consequently, he served as the Second President of the United States but was also a Vice President for two terms.

However, he did not regard the position was very useful and for a person of his skill and achievements, he believed that the office of Vice President was almost insignificant.