Hello Barbara, welcome to Rootschat!
Men are hard to date! Not a social comment, but men's clothing is hard to pin a date to because their fashions don't change often or dramatically. So, we look for some other clues.
I see the corners of the photo are rounded. Believe it or not, this is an important clue. Photo corners became rounded in the 1870s, so they could be easily slid in and out of photo album pockets.
At the bottom, it says Stockton. If this is a location, there are a dozen Stocktons in England. If it's a photographer's name, a location would be helpful. Where was your ggggfather born, and where did he live?
Is there anything at all on the back? If there is a design, could you please scan and post it? It can help date the photo.
Just a preliminary guess on my part would be mid 1870s...ish
I think that would make your ggggfather in his 60s in this photo, and this photo shows a much younger man. Could it be a generation later?
Cheers for now,
China
