Do you know that there were slaves in the United States? 你知道美国曾经有奴隶吗？

　　Before the mid 19th century, there were many slaves in the United States. 十九世纪中期之前，美国有很多奴隶。

　　When Abraham Lincoln became the president of the United States, he wanted to free all slaves. 亚伯纳罕-林肯成为美国总统的时候，他想要解放所有奴隶。

　　The states in the midwest and northeastern parts of the United States supported his decision and free the slaves living in these places. 美国中西部和东北部各州拥护他的决定并解放了它们州内的奴隶。

　　These states were called the free states. 这些州被称为自由州。

　　How many free states were there? 那时候有多少个自由州?

　　There were 19 free states at the beginning of the civil war. 内战开始之前有19个自由州。

　　However, every state become a free state after the war. 然而，内战结束后每个州都变成了自由州。