The book starts out with discussing the types of things the early settlers were not used to and that includes the northern lights, earthquakes, wild creatures, Native Americans, etc. This required a major adjustment on their parts, an adjustment which was not always successful.
In those things weren't enough there were problems with drunkenness, wolves, diseases, religious intolerance, bestiality and sex. That enough of them survived to actually and up increasing in numbers is kind of hard to believe.
The book also includes notes and a bibliography.