One of the important items to pay attention to when doing research is where did your ancestors work. Did they stay current with their job? Did the job allow them to be mobile? Did other family members work in the same types of jobs?
Depending on where your ancestors were located has a large factor in their employment. The earlier you trace your family back the higher likely hood that they would have lived in a rural type setting. This would mean a completely different type of job than in the city. The majority of people would have been listed as farmers, but there were teachers, blacksmiths, doctors, preachers, and leather workers as well. Did your family participate in the same types of jobs for generations? Were they independent or did they work for others? All play important factors in understanding the decision making of our ancestors.
As we moved closer to the twentieth century and the world became a more industrialized place people moved to Urban settings. The pay was higher and the quality of life often improved. Resources were close at hand and people lived in neighborhoods. Higher likely hood of living in building with lot's of people. Way more contact with neighbors, because they were all around you. Immigrants tended to work in jobs where they did not have to speak in English and they were paid for their muscle. Was a much higher instance of people living in Ethnic neighborhoods. Was your ancestor keeping up with a current job? Did the women in the family work as well? Were they able to advance in status as time went by?
Looking at what our ancestors did for a living and where they lived provide excellent sources for further research. Work records, city directories, church,and school. Identifying occupations of your ancestors helps differentiate them from others that may share the same name. Fathers often taught sons their skills.