Historical clue formulations

• ___ Oro — 2010-07-29
• ___ la Plata — 2007-07-21
• ___ Janeiro — 2007-01-28
• With 85-Down, part of Western Sahara — 1998-10-18
• ___ la Plata — 1998-05-17
• _____ Janeiro — 1994-07-03
• _____ Janeiro — 1994-02-02