The African ancestors of today's black Americans were brought to the US as slaves in the seventeenth, eighteenth, and nineteenth century. They worked on farms, especially the large farms in the southern states. Slowly they became a necessary part of the economic system of the South. Slaves did not have the right of people; according to the law, they were a "thing" which belonged to the person who bought them. They had to obey the orders of their owners without question. They were not allowed to learn to read; their owners feared the educated slaves would begin to think about the injustice of the system and would learn to struggle for their freedom. Slaves had to work long hours in very unhealthy conditions. Their owners had complete power over them. They could be bought and sold like animals. At the slave markets, black children were separated from their parents and never saw them again. Slave owners had the right to punish the slave who broke the rule or was against the system. Slaves were often beaten by their owners or killed. After the Civil War, one free slave reported that his owner killed an older slave who was teaching him to read. In theory, an owner who treated a slave badly could be punished. In practice, however, the law meant nothing. The opposition to slavery began very early in the history of the US — in 1671 — but little progress was made until the beginning of the nineteenth century. By 1804, slavery was illegal in the northern states. But it continued and even grew, in the southern states, which depended on cotton for their economic wealth. Slavery ended in the South only after the Civil War. For blacks, however, the end of slavery was only a beginning, the beginning of a long and difficult struggle for true justice. Choose the correct answer from the four given choices. 1. What is the main topic of this passage?