Wu's personal correspondence arrived at Spencer Research Library grouped in rough chronological order by "Youth correspondence" and then by decade starting with 1980. Spencer Library staff maintained this arrangement and created two groupings: Youth correspondence, 1964-1979 and Correspondence, 1980-2003.

For the Youth correspondence, 1964-1979 sub-series, the correspondence was further sorted into rough alphabetical order. In order to keep this arrangement and to make the material easier to find, staff separated the correspondence by first letter of surname, and some pieces were rearranged in order to match the general alphabetical order of this sub-series.

For the other sub-series under personal correspondence, correspondence arrived grouped by decade, and staff separated the correspondence by year for ease of access. Some pieces were also rearranged in order to match the general chronological order of these sub-series.