Simplify the following text for a Grade 7 native English-speaking person.
Original: Collins became one of the leading figures in the post-rising Sinn FÃ in , a small nationalist party which the British government and the Irish media wrongly blamed for the Rising .
Simplified: Collins became one of the leading figures in Sinn FÃ in after the Rising . This was a small nationalist party which the British government and the Irish media wrongly blamed for the Rising .