A Quest

In researching the role that my ancestor, Cyrus Merriam, played as a conductor on the Underground Railroad in Ohio, I came across an account given by Thomas Gray.  The account was found in Wilbur Siebert papers that are held by the Ohio Historical Society.  In the account, Thomas Gray gives the names of two slaves that he was helping find their way to freedom, Isaac and Anderson.  He also mentions that Isaac and Anderson belonged to a Mary Ann McDonald of Virginia.  

Now for my quest.  I would like to see if I can possibly track Isaac or Anderson to see if they did find their way to freedom.  There isn't much to go on.  Just two names and the name of the owner.  I just feel this need to know.  If I can find the information that I seek, that will be fantastic.  If not, I've gained some knowledge in how to track African-American lineages, something that I have no experience with.  So I see it as a win-win situation either way!