In order to be useful, you need to find a map which shows those details you desire -- if you want to plot a migration trail, you would probably want a state or country level map. If you want to track ancestors in nearby cities, a county level map would be your choice. Where do you find these maps? A local historical society or library should be able to fill you in on what maps are available in the area of interest. Plat books are always useful for showing homes as well as property boundaries. Fire maps are good for showing businesses and homes in a city (check the local county courthouse for availability of both types of maps). In addition, there are a variety of historical map sources online, which will be discussed later in this lesson.

If you use censuses to search for family data, you can take the street, ward, district and city information and make maps showing the locations of all the family members. Plotting the migration pattern of families over the various census years often leads to other locations to search.

One of the best books out for U.S. census researchers is Map Guide to the U.S. Federal Censuses, 1790-1920, by Genealogical Publishing Company, Baltimore, 1988 which shows all the U.S. County boundaries for the census years 1790-1920. This is an excellent guide, and should be consulted if the area you are researching has undergone boundary changes.