The Glenside Hotel is actually in county Meath... but is minutes away from border of county Louth... in parts, houses on one side of the road are County Meath and on the other side County Louth!..These days Drogheda is definately in County Louth....
John Sheridan could have been born near St Marys Church
http://ireland.archiseek.com/buildings_ireland/louth/drogheda/st_marys_rc.html...which today is in County Louth.. but I have seen it been said to be in County Meath before.. seems to have been a bit of a grey area years ago... Contact details for St Marys Church (will be able to advise where you can access records etc):
St. Mary's Presbytery
Dublin Road.
Tel: +353 41 9834958
Fax +353 41 9845144
St. Mary's Parish Centre/Office
24 James St.
Tel: +353 41 9834587
Tel: +353 41 9838347
I don't know the history of St Marys Hospital, nowadays its a hospital for the elderly. You may wish to contact them - maybe John Sheridan was born here..:
St Mary's Hospital
Dublin Road
Drogheda
Co Louth
Telephone: +353 41 9838680
Fax: +353 41 9844970
Another idea would be that he was born near a historical bridge named St Marys
http://louth.goireland.com/scripts/low/xq/asp/areaid.186/areatype.C/cat.9/SubjectID.155/PremisesID.11896/qx/premises.htm .. these three places are all within walking distancy ... so perhaps the whole area at the time was known as St Marys....
Have no idea if this helps at all..Kind regards, Karen