It's a frustrating experience going through old photographs that aren't labeled on the back. Sometimes you can tell who people are from what else is in the picture, or who they are with. Sometimes you can make educated guesses, but those guesses can turn out wrong.
For example: There is a photograph from the wedding of my great-grandfather's brother, Harry Feinstein.
Family identified the four men standing next to him as his brothers. However, I knew this couldn't be the case as the youngest brother would have been 7 at the time of the wedding. Ultimately I found a newspaper article listing all the groomsmen and bridesmaids. I still can't for certain identify which is which, but I have a list. The newspaper article didn't identify the flower girls.
So what do you do when you find an image of an alleged relative online? Do you trust that the photo was identified correctly? The two images below are identified as Andrew David Van Every (1795-1873) and his wife Nancy Lucinda Van Sellas Van Every (1803-1880). They were my third great-grandparents. They would be the only third great-grandparents I have photographs of.
Photography existed in the 1860s and 1870s. And the photographs look contemporary to that era. I've contacted the individuals who posted these images online to see if they have more information - such as what year they were taken. But knowing how easy it is to misidentify a photograph, I hesitate adding these photographs to my collection with any certainty.