Lancaster, R. Kent.   1999.  "Almost Chattel: The Lives of Indentured Servants   At   Hampton-Northhampton,   Baltimore   County." Marvland   Historical   Magazine.   94   (3):   341-362.
Compares  the  lives  of white  indentured servants  and  black slaves.
Starke,  Barbara M.  (September-October,   1978)  "A  Mini View of the Microenviroment of Slaves and Free Blacks Living in the Virginia and Maryland Areas  from the   17th Through The   19th Centuries."   Negro  History  Bulletin  41,   878-880.
Highlights the living conditions of slaves and free blacks in Maryland  and  Virginia  from  the   17th  through  the   19th centuries.
Wright, James.   1921. The Free Negro in Maryland:   1634-  1860.    New York.
Discussion on why  Maryland had a large  free black population when  Maryland society had no  comfortable place  for  it.