Breaking through a “brick wall” is often achieved by obtaining a piece of evidential information that proves that only one of many candidates can logically and uniquely be the person sought. Large genealogical companies like FamilySearch, ancestry and Findmypast are constantly trawling knowledge bases for content for re-sale or for educational or religious reasons and they bring together the very minutiae that can achieve this aim and import it into their huge data bases. The expert genealogist, specialising in breaking down “brick walls”, is intent upon teasing out these pieces of information from banks of “big data” and matching them to an individual and his family.
For example a military recruitment record will routinely record the height and physical description of a serviceman from his medical examination. He may have a common name and come from a large city and have been indistinguishable from other men of the same name and age and this may have become a “brick wall”. Until that is one of the larger genealogical entities negotiates to purchase the right to index, for example, a collection of Court Case files that also contains a physical description of detainees and information about their birth. When these details are joined in a single large index to the military records the big data machine finds the match and the wall comes tumbling down!
One of the ways to break through is to keep returning to the large search engines of these genealogical giants because they are constantly adding to their collections. This of course takes time and diligence as well as money in the form of subscriptions which soon mount up. You may be better off employing someone whose job requires them to monitor these collections and to know where the relevant details are located.