Cataloging US history

[Fred Muller Newton <fmuller@EARTH.PLANET.NET>]

I do not blindly use copy cataloging but rather try to catalog relative
to my library using Dewey guidelines.  Lately I have been questioning
where I have my US history books for specific battles.
      Currently I have them in the State's location with a location code
afterwards.  ie Pilgrims and such are in MA, Battle of Yorktown is in New
York.
      Should such things be in US history or in their state's history?
Let's make this a general discussion.
                 Fred Muller