I don't know anything about the history of that law but it passed the house almost unanimously and the Senate wasn't split along slave/free lines. It didn't hav

I don't know anything about the history of that law but it passed the house almost unanimously and the Senate wasn't split along slave/free lines. It didn't have the effect of hurting slavery and it's conceivable the slave-state legislators thought it would boost local production (of slaves)