I really got a surprise last night while snooping at the Florida Memory Photographic Collection. I searched on "Fort Pickens" and found only 114 pics, but several of them completely changed some things I believed about the fort.
The first pic dates to 1976, just a few years after the National Park Service took over the fort. It shows a Ranger and some visitors on the parade ground with the fort's north wall behind them. The big arch is the sally port--the main entrance. To its right is a low square doorway instead of the pair of tall rectangular openings that are there today. I was all set to write to the site's owners to tell them this isn't Fort Pickens.
Then I found this next picture, from 1957. Even though it's reversed, there's no mistaking the parade ground if you've been climbing all over the fort for a few years. There's that little doorway...and up on top, over to the left, is another thing that's not there today, a low concrete range-finder station. All that's left of that these days is a set of concrete supports for the stairs, just behind the restroom building.
I like the cars parked in the parade ground. Before the National Park Service got the fort, Pickens was a Florida State Park. No parking there, today. At some point, the NPS folks re-worked that small doorway to match the tall double-doors that were supposed to be there. The other doorways were neatened up, too.
Next, from 1955, shows the parade-side arches of the southwest wall from the top of the northwest wall. In the distance are the twin arches of the cistern. The mystery wall from a recent Pic of the Day is visible as a dark square just to the right of the smaller arch. I was thinking that the Park Service built it to keep people from climbing onto the adjacent walls, but it's clearly older than I'd thought.
The last shot, also from 1955, shows the arches of the northwest wall, all bricked up with doors and windows. A chimney pokes up from the last complete room; just north of here (out of frame, right) is the big hole in the fort left by the 1899 explosion that destroyed the northwest bastion.
Today, you can see signs that those arches were walled-up, but they're all open and neat, these days. The partitions were taken down sometime before 1982, going by one picture at the Photographic Collection site.