James have you tried searching at the Maryland Archives?

I did a search of BARNES on the wonderful Slavery site, hope this helps.

The regular link to the Maryland Archives isn't working for me but this did tonight.

The slavery link is awesome.
If you have the names of Slave Owners, there is an interactive link too!

Good Luck!
One of these days we are going to find out we're related.
My mothers MANNS side of the family is from Anne Arundel Maryland.
http://ww2.mdslavery.net/dsp_searchresults.cfm?fn=4&search=1