Simplify the following text for a Grade 12 native English-speaking person.
Original: In response , the Manchester Patriotic Union , a group agitating for parliamentary reform , organised a demonstration to be addressed by the well-known radical orator Henry Hunt .
Simplified: In response , the Manchester Patriotic Union organised a demonstration to be addressed by the radical orator Henry Hunt . The Manchester Patriotic Uniona was group agitating for parliamentary reform .