The ACBL's web site lists NABCs only back through Fall 1996. For earlier NABCs (formerly called simply "Nationals"), the source was the Encyclopedia of Bridge as compiled at http://newsgroups.derkeiler.com/Archive/Rec/rec.games.bridge/2011-12/msg01552.html.
You'll note that there are a lot of these, for a history of 85 years; that's because while there was just one in 1927 and one in '28, after that there were two Nationals a year, and then three per year starting in 1958. |