Doolan, St. Louis, Mo

My Grandfather, Richard Henry Doolan, was one of three childred born to ?Doolan and Mary Theresa?One of these children, a boy whose name I don't know, was stolen, supposedly, by a member of the family who took him away from St. Louis, MO.
He was born c 1850.Does anyone know of a Doolan who was adopted at about that time?