It could be a developed glass negative but the back of the image shows the typical cardboard backing of a CDV. The image is fantastic, an African American family on the porch of their home. This would have been around the turn of the century, meaning this family had done well and been prosperous, a rarity for the time. On the back is the name Clara M.
A quick search indicates there are several women this may be. A well off black family in this period will likely be well known, aiding further research. Do not miss this photo, you are likely not to see another!