Focused in Porto Feliz, captaincy/province of São Paulo, this study analyzes how family reasons influenced conflicts between masters and slaves about freedom and slavery. At the ends of slavery, with pressures for freedom and relative loss of legitimacy of slavery, a master family tried to preserve its social position, built up over generations and over slavery. By other hand, slaves families sought to achieve freedom. Thus, a former slave family and a slave family joined forces to defend their kinships interests
slavery; kinship; social mobility