According to Marx and Engels, what has the
bourgeoisie sacrificed in pursuit of free trade?

One effect of the dog barking at the slaves was they were captured and arrested.

Explanation:

The question is based off an excerpt from the book "The Underground Railroad: A Record of Facts, Authentic Narratives, Letters, & c." In this excerpt, the slaves are in Terrytown, Maryland. They are hiding in the woods and a man walks near them and starts to split wood. He has a dog with him and the dog starts barking at the hidden slaves. The man comes and finds them and is very nice, he gives them advice and offers his barn to hide and get some protection. The man and his daughter cooked for the slaves and they had a big breakfast, they were then told to go rest in the barn and he would show them the way to Gettysburg in the evening. However, one of slaves had a bad feeling and didn't sleep. He stayed awake and heard men outside and the farmer giving them up. They were all captured and arrested after a brief struggle.