Underground railroad kept in mind that they don’t attract any attention towards them. So they used to transfer people from America to Canada in a very small number. A larger group or a larger number of people could obviously attract attention. In one group there was mostly 1-3 people. After escaping the guards and be free out of the danger zone, the “passengers” had to walk 10 to 20 miles at night. Yes it was a long distance, but the reward was more important. As we say that destination is more important than the journey.