The final years of Macintosh’s life, spent in Eisenach in Saxony, are preserved in only a handful of sources (or only a handful that I have so far been able to find). One of the most curious and evocative is the journal of Aaron Burr, which records successive meetings with Macintosh over the course of two frigid days in January 1810. During the second meeting, Macintosh told Burr about his earlier correspondence with George Washington (about which he was evidently very proud) and that one of Washington’s letters to him was on display “in the museum at Weimar”.

Over the years I have, from time to time, idly and unsuccessfully tried to find out which museum was being referred to and have always drawn a blank—all the existing museums in the city postdating 1810 by some distance. This weekend I posted on Bluesky a plea for help in identifying the museum and, much to my surprise, the curator and environmental historian Dominik Hünniger was able to do one better and find the actual (digitised!) letter, which is now in the care of the Goethe- und Schiller-Archiv in Weimar. While more work needs to be done to understand where the letter was before it joined the collections of the Archiv, it’s nice to be able to tie up one of the innumerable loose ends of this project.