You'll need to identify the key developments and moments in time that helped to shape the educational landscape of your city.  You may want to search in newspapers, both local and national, for events that were important or could be considered turning points.  You might also want to search in larger collections like CatQuest or Google Scholar for mentions of these historical events.

To search local newspapers:

1)  Find out the names of the local newspapers in your city.  Googling should identify at least a few newspaper titles.

2)  See if we own them by putting the title into the "Journal Titles" portal.  Click on "Journals" below the search bar on the Howe Library site (see below).
 

3)  Once you are in the newspaper, use some broad search terms to begin exploring.

Both CatQuest and Google Scholar index information from many different places: scholarly journals, reports, newspapers, government information, and more.  A search with the name of your city, "schools," and "race" or "racial" can often yield fruitful initial results.  Once you find out more about the events that shaped education in your city, search again with the specific events to find out more.

Wikipedia also provides a good starting place for overview information and can lead you to other resources.