It would take 31 hours to reach California from Illinois by car. Of course, in the 1800s they didn't have cars. It is estimated to take 636 hours by foot. That is almost a month, and depending on the family's size, that can be a lot of food and water to tale. There were also diseases, and if they weren't in a town then it would be hard to help care for the ill. The current weather and seasons could also harm the family.