Bought this under the assumption that it was Seattle, Washington. (It has Seattle written on the back.) Upon receiving it in the mail I realized it was definitely not Seattle. Seattle is hilly. It was even hillier at the time this photo was taken. If you look closely you can make out riverboats along the shore. You wouldn't have found those in Seattle. There is also a tall masted ship in the water. A river town isn't likely to be able to accommodate an ocean going vessel unless it is near the ocean as well. The town's architecture and layout isn't right for Seattle either. The biggest clue is the tall building facing us in the foreground. It says "Pelton and Dunbar" on the front. Pelton and Dunbar was a sugar manufacturer in the late 19th century and they were based in New Orleans. New Orleans would seem to fit the other details as well, so I'm gonna say this is New Orleans, Louisiana.

I believe this was taken from the steeple of St. Patrick's Cathedral looking towards the river. That would make the intersection in the foreground Magazine and Girod Streets.

Here is a modern day view from that point: