The button is a mid-1800s-or-later European-style Livery button, probably made in Britain, or perhaps aome other European country. For anybody who doesn't already know ehat a Livery button is... wealthy European Aristocracy families provided uniforms for their household servants (such as butlers and coachmen), and the uniform's buttons often (but not always) showed the family's Aristocratic rank and family Crest or Coat-of-Arms. The 9-balls crown on the button you found indicates the head of the family held the rank of Viscount. The emblem below the crown shows the family's distinctive Crest or Coat-of-Arms.