John Merryman was a FARMER and is listed in such in the Baltimore COUNTY census (the City of Baltimore is not part of Balimore COUNTY) - he was not a judge, lawyer, politician, doctor, banker or any other profession customarily travelling in high society.
John Merryman inherited the main property in 1847. That, however does not preclude John Merryman from also having a residence in Baltimore. In fact, just a few minutes of searching showed that Baltimore was crawling with Merrymans. They were a very prominent family in the area.
Merryman inherited the farm from his uncle - Nicholas Bosley. Here there are a lot of Smiths locally, but none are members of any aristocracy. In contrast, there is one family with a unique last name, worth several hundred million dollars. I guess they are not members of any aristocray by your definition? But could you provide the address of this alleged home in Baltimore City?
Just a little more searching shows another connection. A number of members of the Merryman family were married or buried at old St. Pauls in Baltimore (John the traitor was not one of these - he is planted in Sherwood).
But how does that PROVE that John Merryman was a member of the "Maryland aristocracy"?
John Merryman was at one time a leader in the State Agricultural Society, located in the City of Baltimore
Can you provide the address, and when Taney attended these meetings?
He was a wealthy landowner from an old and prominent family. He occupied several positions of civic importance, befitting his position in society.
P.S. I noted in another post that the City Baltimore was not part of Baltimore County after 1851.