“We really did turn these places around,” Mr. Close said in an interview. “My school in Bridgeport had 60 percent truancy and it just eliminated it.”
In a statement Friday, a White House spokeswoman said that Mr. Trump was going to disband the panel anyway.
“While the committee has done good work in the past, in its current form it simply is not a responsible way to spend American tax dollars,” the statement read.
The committee never convened under Mr. Trump, members said, and the president has not appointed members so far. The 16 who resigned Friday were appointed by President Obama and had elected to stay on under Mr. Trump, several said, to try to have an impact in his administration. More than a dozen additional committee members had resigned earlier rather than serve under Mr. Trump.
“We thought that perhaps we would be able to do some good from within because the arts and humanities are critical to an enriched society,” said Fred Goldring, an entertainment and media entrepreneur on the committee. “In the end we decided we just weren’t going to be able to be effective.”
Andrew J. Weinstein, a Florida lawyer on the panel, said he was contacted by the actor Kal Penn, a fellow member who had worked in the White House Office of Public Liaison under Mr. Obama, and discussions ensued about drafting the letter as text messages and email circulated among the group. Mr. Weinstein said he hoped their resignation would bring attention to the importance of the arts at a time when President Trump has proposed eliminating funding for the National Endowment for the Arts and the National Endowment for the Humanities.
“We know the importance of open and free dialogue through our work in the cultural diplomacy realm,” the letter said. “Your words and actions push us all further away from the freedoms we are guaranteed.”
Mr. Penn said that everyone agreed it was time to end the group, though some expressed consternation about abandoning a committee dedicated to promote the arts.
“You sort of have hope up until a certain point,” Mr. Penn said, “and then you have to realize we just don’t want our names attached with this.”
“It’s not for the news cycle,” he added. “It’s for how are we going to view our opportunity between right and wrong here.”
Ms. Lahiri said that folding the committee in the wake of Charlottesville was not a hard call.
“The thought of advising a president capable of doing and saying the things that Trump has been doing and saying seemed like something that just did not sit right in my heart and my soul,” she said in a telephone interview from Rome. “I think everybody felt the same.”
Indeed, Mr. Mayne called Mr. Trump’s comments in support of the nationalist protesters “antithetical” to the whole meaning of art “as a territory which is inclusive.”
“The essence of our work is about conversation and discourse and dialogue,” he added.
In conclusion, the letter goes so far as to suggest that the president himself step down. “Supremacy, discrimination, and vitriol are not American values. Your values are not American values. We must be better than this. We are better than this,” it says. “If this is not clear to you, then we call on you to resign your office, too.”
So far, Mr. Penn said, the committee has not received a response to its letter.
Ms. Lahiri said this was not surprising. “Do I expect a reply? No,” she said. “But this is necessary closure at this point for a group of people who remained hopeful that the committee would be able to do some good and much needed work, in spite of our feelings about the current administration.”