After reading the IBR CWRT pages the other nite, I noticed its mention of where Gen'l Richardson passed away as the "Fry" house: Roundtable. Curious, I went to my Trailhead Graphics map to find the "Fry" house. There ain't one. It's the "Pry" house. Not only that, but the "Pry" house is a place that deserves a visit next time.
According to the Park Service website, the house is now not just the site of McClellan's HQ but also a battlefield hospital museum: NPS . It is, indeed, up on the second floor where Gen'l R succumbed to his wounds several months after the battle: Civil War News. The museum is connected to the national museum of Civil War Medicine: NMCWM. There appear to be many events associated with the house during the remainder of '08 and into '09: calendar
Not sure how much I would really want to investigate this aspect of those times, but one observor calls it a must-see: CW Journey. I guess my next visit to Antietam will just have to include...
...the "Pry" house.