what does that do?

该如何是好
It cordons off and it contains and it begins to smother

这会使南方社会以及奴隶制
Southern society and the slave system.

受到阻挠和压制
And the theory was that on the rim of the South, in Kentucky,

这样会导致南方边缘地带肯塔基
in Missouri, in Maryland,

密苏里马里兰等地
the price of slaves would begin to dwindle.

奴隶的价格会开始降低
And then what do people do when the price of something goes down?

然后人们在物品降价时会怎么做呢
They sell it off.

廉价抛售
Where are they going to sell those slaves?

他们会把那些奴隶卖到哪去呢
Can't sell them west, can't sell them to the Caribbean--

不能往西卖不能卖到加勒比
international slave trade's illegal.

跨国奴隶买卖是犯法的
They're going to sell them into the Deep South.

他们会卖到南方腹地去