A good place to look would be the local newspaper's real estate section. You can cross-check the big advertisers with searches on google, yahoo, and MSN. When you find an agent and/or company that shows up in both searches, that's probably your answer. The local Realtor association may be able to help you with that as well.
are you looking fro statistics or for an agent who works in Federal Hill? I have sold and listed a number of homes in this area (condos, singles and multi families. If you would like more info please contact Lorraine at : firstname.lastname@example.org