I have frequently commented both in oral presentations and in writing, that genealogists too often ignore the historical context of their investigations. Research cannot be conducted well in a vacuum. A good example is the so-called "Irish Potato Famine" (Irish: An Gorta Mór) or the The Great Hunger. During the period between 1845 and 1852 it is reported that the Irish population was reduced by up to 25%. Now, if you think about this for a minute, you can see that due to this cause and many others there is an explanation, in part, for the huge Irish immigration into the United States. You can also surmise that the upheaval in Irish society caused by the emmigration and the famine may have affected the record keeping. Wikipedia. My own Irish ancestors left Ireland during the Great Famine and emmigrated to Canada along with hundreds of thousands of others.
The above is just one example of the impact background history can have on genealogy because first and foremost, genealogy is history.
The need for historical context is constant. Another example, many Americans trace their ancestry through Ohio. Late in the 1700s some of this land was known as the Western Reserve of Connecticut and was subject to a series of land speculations and developments. Without understanding how the land was developed and sold, it is nearly impossible to understand the movement of the families who purchased land from the developers during this time.
The examples go on and on. You cannot really understand your family without also understanding the historical context. Begin by reading a general book on the history of the area where your family originated. Then become more specific. Read about the local area and gather information about settlement patterns, land ownership, church membership and other historical details. All of this information will be useful in building a real understanding of your family and in extending lines and finding lost family members.