Kathleen, I was able to obtain maps from the Library of Congress (free) for Saginaw, Detroit, and Flint, just by going to their website and "asking a librarian" the newest of my maps was 1917 for Detroit. Imerely asked where I could find maps for those cities for the period from 1910 to 1925. They have been very helpful in determining what wards to look in on the census as well as in the case of flint my grandparents lived on a street that is now part of I75. hope this helps. Ken Wood