Is it legal to own chickens in Frederick County?

I live in Frederick, Maryland and own Chickens. I live in a townhouse and have two hens in a coop in my backyard. Before i got them i checked to make sure it was legal and i thought it was, but some random inspector basically knocked down my door and told me that we aren't allowed to any livestock whatsoever. I need an answer as soon as possible and please answer only if you are 100% sure it is legal. Thanks