That's not just Maryland. In all states I've ever lived in, information about deeds, titles, mortgages, and values of any real estate (not just homes, but commercial and agricultural properties as well) is considered public information. You've always been able to walk into the county courthouse and ask to see information about leinholders, titles, and mortgages for any address; indeed, even housing blueprints must be files with the government, and you can see the blueprints for any building on any property.
You can also see information about the general contractor responsible for the building on any property, financial information about whatever bank financed the construction, and so on.