Grow a lot of food and import alot of food
In the underground railroad, there were safe places that the slave hid and slept that were called "safe houses" or "stations". The slaves traveled in a couple set of routes with regular paths. The slaves hid and slept in stations during the day and then traveled at night, because the slaves owners were looking for them during the day, so the slaves would be safer if they hid and slept during the day.
Therefore the answer that you are looking for is,
All of the above.
I hope that this has satisfied you.
