You can use any of the following to back up your answer:

Refugees
Managed to return a lot of refugees back to their home land

Working conditions - ILO (international labour organisation) successful in:
Limiting children's working hours
Banning white lead from paint
Campaigning for improved working conditions

Health
Worked to stamp out leprosy
Campaign to get rid of mosquitos

Transport
Recommended marking shipping lanes
Produced international highway code
Social Problems
Blacklisted companies involved in illegal drug trade
Freed 200,000 slaves in Sierra Leone
Challenged forced labour for railway building in Africa
Looked into problems such as slavery, prostitution, and drug trafficking.