As an undergraduate, Weld was: the most popular member of his class, and this without seeking it, without any concession of principle, by virtue of his sterling worth, his elastic spirits, and his strong social sympathies.
Weld spearheaded a 14-year effort that secured passage of the 1865 law authorizing Harvard alumni to elect the members of the Board of Overseers.
His obituary in the Boston Evening Transcript described him as a "bright, cheerful, warm-hearted man who preserved, as a winning grace, his childlike simplicity to the last," and noted he possessed "in every way a genial nature" and lamenting the loss of "the beaming pleasantness of his companionship.
"[3] In 1870, William Fletcher Weld donated money to Harvard for a dormitory to be built in memory of his departed younger brother.
There is an inscription on the dormitory which (when translated from Latin) reads "To Stephen Minot Weld, a man well-deserving of the University, dedicated by his brother."