But does that cover promoting civilians?
The official commission script just mentions appointing [insert name here] as an officer, in the name of the President. After which said person is no longer a “civilian”.
Darn, I was reading the same document, and missed that bit.
Still not sure about the ability to to anything for a civilian. The president may have power to delegate, but the legal structure for the actual commissioning is another matter. The president can’t create that.
According to the official US constitution the President “…shall Commission all the Officers of the United States.” Pretty clear that the President has the ultimate authority to do so, which is why the delegates act in the name of the President, not on their own authority.
Starfleet has always been kind of an Age of Sail analog, with ship missions often putting them far away or out of communication with higher command. The US Navy in the 18th and 19th Century is probably where you would find historical American examples of this kind of civilian commissioning.
I don’t know that there was ever really any reason/opportunity to do some sort of weird field commissioning of civilians into the US armed forces. If it did happen in WW2, I’d guess it probably happened during the Japanese invasion of the Phillipines, and some poor civilians working with the military just got sort of sucked in and slotted into the rank structure by way of what the OP is describing.
But that’s entirely whimsical speculation without any basis in fact. Fantasy even. I don’t think there’s any basis for press-gang type stuff in the US military, especially not for officers. Like I was saying, I suspect it’s one of those situations where it just sort of happened organically, and then some higher officer said “Harry, you’re a Captain!” without necessarily forcing anyone to do anything.
What did happen a LOT was that they’d draft civilians with certain relevant skills and education and do what’s called “direct commissioning”. Think Hawkeye Pierce- he was a surgeon prior to the Korean War, they needed doctors, so they drafted him and made him a Captain, as that’s the customary rank for professionals like that who are directly commissioned.
The thinking is that certain levels of education and experience merit coming into the military with roughly their civilian world level of authority and respect. So they’re directly commissioned as officers, with rank commensurate to that. This still goes on today, although not in a conscription sense. Just the other day, a cardiologist in his sixties from the DFW area was commissioned a Lieutenant Commander in the Navy’s medical reserve. I’m guessing he was commissioned a Lieutenant Commander (O-4) because he’s older and more experienced than the younger doctors getting commisioned straight out of medical school.
The Wikipedia article on impressment mentions several cases of press-ganging in the Continental Navy and one case in the 19th-century US Navy, so it was definitely a thing, even if (after the Revolutionary War) it seems to have fallen out of use.
In World War I, my great-grandfather Milan entered the Serbian Army as a common soldier. But he was very brave, and managed to work his way all the way up to Major. After the war, he could have stayed in the Army, but respected his mother’s wish to demobilize and take care of the family’s agricultural land/work in one of several family businesses. Had he stayed in the Army, he might have had to travel with his family to different garrisons around Jugoslavia, but would have had a steady income. The family businesses he was involved in, however, did not do well for various reasons, including the Great Depression, and my grandfather grew up in relative poverty. When my great-grandfather heard that the Army was offering free officer training, he decided that my grandfather would become an officer and made him sign up for the military academy; upon graduation, it fell upon my grandfather to help support his family.
Practically speaking it hasn’t been part of the US military’s bag of tricks since the Revolutionary War.
I think part of the OP’s confusion may be that Star Trek is generally sort of weird with their military stuff- Roddenberry claimed they weren’t military, but then they have a captain and an essentially naval rank structure, and they fight stuff on an armed ship in the name of the Federation. This weirdness extended to ST:TNG, in that they have Picard giving Wesley a commission as an “acting” Ensign, and nobody protests or even bats an eye, as if this was a perfectly normal and reasonable thing for him to do in peacetime conditions when they weren’t too far away from Federation space and a Starbase. I mean, what could have the justification have been for Picard to have kept Wesley on board as an “acting Ensign” any longer than it took for him to get to a Starbase and have Wesley sign up for Starfleet Academy?
At least in ST:Voyager, it made sense, in that you had a bunch of Maquis and Starfleet people thrown together after being zapped halfway across the galaxy, and that at least of the main Maquis characters, Torres, Chakotay and Paris were all former Starfleet officers. They didn’t have much choice in the matter- Voyager needed people, and the Maquis were qualified.
But fundamentally, the writers did whatever helped their stories.
The Marquis de Lafayette’s Revolutionary War story doesn’t quite fit the OP’s conditions, but it’s interesting all the same.
Lafayette was a 19-year-old dragoon captain in France recruited to fight in the Revolutionary War by an American agent. When he arrived in the U.S. (then governed under the Articles of Confederation), the Continental Congress was convinced to offer Lafayette an apparently honorary commission as a major general (!).
Within a week of this commission, Lafayette met George Washington, hitting it off with the American general immediately. The Frenchman returned with Washington to the American’s camp and became part of Washington’s staff.
Initially, Washington advised Lafayette that he’d never be offered command of troops because of his foreign birth. Weeks after that talk, Lafayette impressed Washington with his actions during the September 1777 Battle of Brandywine (specifically, helping shepherd an orderly retreat while wounded by musket fire). Two months later, after Lafayette recuperated, Washington offered him formal command of a division. Lafayette’s first command was during the November 1777 Battle of Gloucester, where he personally ran reconnaissance and led the final charge to overcome a group of Hessian mercenaries bent on capturing Fort Mercer east of Philadelphia.
After the Battle of Gloucester, the Continental Congress formalized Lafayette’s commission as a major general in the Continental Army upon Washington’s recommendation.
I wouldn’t say I was confused as such. Rather, I noticed that Starfleet seems to practice something admittedly unusual with respect to commissioning, and so decided to ask here if there’s any real-world counterpart.
OK, now I think you might be the one who’s confused. 
Torres had never been a Starfleet officer, and Paris was not a member of the Maquis at the time the series started. While he had briefly (like, for a few days) worked for them, he had already rejoined Starfleet before Voyager was cast into the Delta Quadrant, albeit as a uniformed but unranked adjunct. So the field commissions he received were internal promotions rather than Janeway commissioning a civilian from outside the ranks.
It does help that in the TNG universe they do not have to worry about justifying payroll.
And if a real-world ship were to somehow find itself in a situation comparable to Voyager (cut off from their home and command structure for many, many years, in a desperate fight for survival), they probably would do things like that, even if it wasn’t actually “by the book”, because when you’re in an out-of-the-book situation, you respond with out-of-the-book actions.
The Surgeon General, upon appointment, is automatically granted the rank of Vice Admiral (O-9).
Does that meet the specifications of the OP?
No, but she went to the Academy, dropping out at age 19 only after being suspended for her temper. She was apparently actually doing well in most of her classes, and thought to have a lot of potential—which she later realized as part of the Maquis.
I’m also not sure I would consider what Paris got to be an internal promotion. He was working with Starfleet outside the ranking system. If it was an internal promotion, then it wouldn’t make sense why Janeway said she couldn’t promote Ensign Kim.
Amend that to “It doesn’t make sense why Janeway couldn’t promote Ensign Kim”. Unconditionally. Even under normal, real-world rules, she could do that.
Voyager stuff aside, my point is that pretty much all of them were former Starfleet in some capacity, and therefore familiar with the ways that things were done, especially Chakotay and Paris, who had both been full-fledged officers beforehand.
That’s a bit different than say… dragging someone totally unfamiliar with the military in and putting rank pips on their collar.
Is the public Health Service supposed to be military, though? This should be Department of Health stuff.
In the United States, there are two Uniformed Services that are not part of the Armed Forces: The NOAA Commisioned Corps and the Public Health Service Commissioned Corps. (In contrast, the uniformed Armed Forces are the Army, the Marine Corps, the Navy, the Coast Guard, the Air Force, and the Space Force.)
The unarmed Uniformed services’ rationale goes back to the predecessor of the NOAA Commissioned Corp working alongside the Union military during the U.S. Civil War. (Doing battlefield and coastal surveys.) Their presence in the field without the legal protection of uniform and formal command meant they could be executed as spies if captured by the Confederates. So they gained uniformed status that has stayed since. The Public Health Service added a uniformed corps a couple decades later, apparently because a military-style public health and mobile hospital system needed military discipline and structure.
Are they military? The have formal military discipline and organization. They are unarmed, but their chains of command can be directly attached to military command structured so that they receive binding orders from Armed Forces commanders. The only distinction from the Armed Forces is that they’re unarmed.
Yes, they’re military.
That’s what I’m trying to say as well; if we can come up with any examples in the US military of something similar, they’re going to be some unconventional situation - the retreat in the Phillipines in 1942, or something along those lines.