Donated by John C. Green and named for his brother, Henry Woodhull Green (a Princeton alumnus and Chancellor of the state of New Jersey), the library was an elegant octagonal structure featuring a striking central rotunda --then the most lavish building constructed to date on the campus. Chancellor Green Library was located to the immediate east of Nassau Hall and faced Nassau Street. Both its prominent placement and the high costs of its design and construction reflect the library's importance in McCosh's scheme for the College's institutional development.

Princeton's first purpose-built library was converted to other uses in 1946. When the High Victorian Gothic style fell out of favor, trees were planted to screen it from Nassau Street. (Later, the Joseph Henry House was moved in front of it, almost completely blocking it from public view.) Even so, it remains one of the real architectural gems on the campus. And perhaps most significant, the success of Chancellor Green Library marked the beginning of a three-decade partnership between Potter and Princeton that eventually produced Witherspoon Hall, Alexander Hall, and Pyne Library.