Simplify the following text for a Grade 1 native English-speaking person.
Original: While salt is now plentiful , before the Industrial Revolution salt was difficult to come by , and salt mining was often done by slave or prison labor . In ancient Rome , salt on the table was a mark of a rich patron ( and those who sat nearer the host were above the salt , and those less favored were `` below the salt '' ) .
Simplified: A salt mine is a mine where salt is taken from the earth .