The process used to determine which of the Madison-era doorframes was the right one for the South Passage's southeastern doorway involved collecting information from three sources.  First, the construction date of each of the reused doorframes was determined.  Because each of Montpelier's three Madison-era building periods used different moldings and construction details, it was relatively easy to separate the reused doorframes into three groups.  After the reused doorframes were dated, it was possible to narrow the focus of the investigation down to the three reused doorframes that dated to ca. 1764.