Thousands of city directories are going online.
City directories are a basic tool for genealogists. City directories are like an annual census of the cities and towns across America. Now – thousands of them are being digitized and put online.
Download and Keep this book in your personal library!
City directories usually listed all adult residents of the community. Typical entries give:
Name; address; occupation; relationships; notification that a person moved & where they moved to; divorce dates/remarriages; widows etc.
Here is an example of entries identifying widows – giving the names of their deceased husbands in the Indianapolis 1914 City Directory. 
Google Books
Internet Archive
Google Books
Google Books
Google Books
Google Books
Internet Archive has over 2,300 city directories online and Google Books has over 1,000 city directories online. These directories are not on GenealogyBank. All genealogists should use those sites to find city directories. Good things are happening all across the Internet.
It is a great day for genealogy!