South of Harlem Avenue there are about 10 streets whose name begins with the letter "O" (Oceola, Ozakam, etc.). Do you know the reason for this?
I believe you are referring to the "O" grouping of streets about 16 running west of Harlem and roughly north of Belmont. These include Osceola, named for the Seminole Indian Chief, and Ozanam, honoring a French founder of a Catholic charitable organization - the St. Vincent De Paul Society. I found that information in our Streetwise Chicago by Don Hayer and also available in part online from the Chicgo Historical Society at
I also checked our Encyclopedia of Chicago, our Local Community Fact Book Chicago Metropolitan Area, for information on real estate developers of the Dunning and O'Hare Community Areas as I speculate those names were decided upon at the time by the real estate interests selling houses. There are other sequences of coinciding initial letters of successive streets in Chicago for example the "L's.
I could not find any further information that would fully answer your question as to why all the O's there.
Perhaps the Northwest Chicago Historical Society
Northwest Chicago Historical Society
PO Box 30067
Chicago, IL 60630
or the Chicago Public Library might be able to help you.
Thank you for the interesting question.
Neil at Reference