He was a great influence to his grand-niece Alice Wilmarth Busing, a painter proficient in oils, pastels, and watercolor.

[12] That same month he was offered the job of Professor of Art at Yale University,[13] but he chose to remain at the National Academy of Design.

[16] An associate was required to present to the academy within a year his own 25" by 30" portrait in oil colors, and an academician a specimen of his Art.

It suggested that "perhaps his arduous duties as Director of the Academy School of Design prevent his giving the time he ought to his art".

He hosted the first meeting in his studio and offered to teach the life classes for free until the league could afford to pay him.

[5] In 1894, Wilmarth wrote an article “Essentials of an Art School” for the catalogue of the 69th Annual Exhibition of the National Academy of Design.

...It is essential in the evolution of any vital, soul-stirring art, that no instruction should discourage, no curriculum of study should retard, no charm of mere handling should supersede the fullest, freest development of the soul-activities of individual artists.”[20] Wilmarth was prominent as a worker in the Swedenborgian denomination, and was a member of the Swedenborgian Church of the New Jerusalem.

He had written considerably on religious and social subjects, and was one of the founders of the New Earth, a Swedenborgian publication, in 1872, and was afterward its editor for several years.