This dissertation examines the diverse ways by which slaves in Ouro Preto, the capital of Minas Gerais province, Brazil, during the nineteenth century acquired freedom through manumission, which is the process of going from being a slave to being a free person within a society where slavery is legal, as opposed to obtaining freedom through abolition. Minas Gerais had a large slave and manumitted population, and manumission had been a common practice in the region since colonial times. This dissertation investigates the unique conditions behind this practice as well as the circumstances of its occurrence and the strategies slaves used to achieve freedom before general abolition. Slaves were manumitted in a variety of ways, such as in the last wills of their slave owners and via self-purchase, which the available data shows was in fact the most efficient way to obtain a letter of freedom. Manumitted individuals also appealed to the judiciary to be granted freedom and to fight against attempts of re-enslavement. This dissertation goes further to examine the exercise of agency by the diverse subjects involved in manumission, including the slaves, the slave owners, lawyers, judges, and local and provincial authorities. The life stories of the enslaved individuals are revealed by the primary sources, even though these are official and private documents often written by the slave owners and local authorities. The slaves’ stories reveal an ongoing, active pursuit of freedom, often after a lifetime of compulsory labor.