This modern slavery takes many forms, but the main one boils down to extreme exploitation of workers, many of them children. The U.S. is not immune to the problem of slavery. 72 Thai men, women and children had been held, some since 1991 in involuntary servitude. These garment workers were locked up, guarded and threatened with death if they tried to escape. Capitalism can never abolish slavery since it is based on wage slavery.
Capitalism lives on profits, on the surplus value it extracts from workers' labor.
Only communism can end all forms of slavery including wage slavery, by abolishing the wage system. Production for need, not for profits, will be the basis of a communist society.