Simplify the following text for a Grade 9 native English-speaking person.
Original: In the late 1960s , a civil rights campaign started in Northern Ireland , to get equal treatments for Roman Catholics Adams was an active supporter and joined the Northern Ireland Civil Rights Association in 1967 .
Simplified: In the late 1960s , a civil rights campaign developed in Northern Ireland . Adams was an active supporter and joined the Northern Ireland Civil Rights Association in 1967 .