Answer:
Being caught again.
Step-by-step explanation:
As the passage says "Those that wanted to stay around that part of Ohio could stay, but didn’t many of them do it, because there was too much danger that you would be walking along free one night, feel a hand over your mouth, and be back across the river and in slavery again in the morning." This explains that they were to scared to stay, because they didn't want to get caught, and if they did they had to go back into slavery.