May 1813
The rush to get the York-built warship out into the harbour and into battle is such that it was never properly christened. Some wag comes up with a suggestion, that they should call it the “Cornwallis” and the new name is made official. Thus newspapers across the world can shout “This Time Cornwallis WINS at York-town”.
The defense of the York harbor meant that all the supplies (guns, cordage, etc.) that were meant for the flotilla on Lake Erie were saved, and were soon able to be on their way. On the other hand, the battle damage to all the ships involved meant a LOT of repairs had to be done to put everything right. On the third hand, there were enough damaged ships that e.g. rigging could be cannibalized from less vital/more damaged ships to repair more vital/less damaged ships.
General Sheaffe's defense of York, while not inspired, was (ATL) resolute, and he stays in his command. [OTL he was disgraced and retired.]
On the American side, their next plan was to attack Ft. George and start working their way up the Niagara peninsula. However, most of the army they were going to use just surrendered at York, and the fleet they were going to use to transport and supply the army with was just eliminated. General Pike is dead, and General Dearborn and Commander Chauncey are captured. Panic strikes.
Meanwhile, Brock has ordered many of the troops that were stationed as far east as Quebec City to start moving west. Now, he received full command over British troops in the Canadas on 1 March, and wanted to move people closer to the front. However, the situation with Prevost was a bit uncertain, especially just how much who was in charge of what. This meant he needed to move slowly. He wrote to Prevost 2 days after he received word of his new responsibilities, with the suggestion 'that all but a minimal garrison be moved from Quebec City as soon as possible', what did Prevost think, and who should issue the order, if it was issued. Prevost wrote back that while he wasn't entirely sure it was a good idea (i. e. he thought it was a horrible idea, but he wants to be polite about it), that London had made it clear that such movement of men and matériel was quite within Brock purview now, and there was no need for him (Prevost) to either issue the orders or even review them. He would, of course, like to be kept informed. ( i. e. I don't want anything to do with this, when it blows up in your face, it's your problem buddy boy. And I want a paper trail.) So, it is not until the middle of April that Brock can get orders out to move men and equipment from Quebec. [I'm exaggerating Prevost's peeve, but he's perfectly aware that he's been bumped out of the line of command. Moreover, just because Brock's excessive impetuosity has worked a couple of times, doesn't mean his luck will hold. Still. Well. Their Lordships command. And hey he gets a nice shiny title out of it. ... OK, so he'll shut up and try to make everything work and maybe it WILL all work out for the best. At least no one will ever be able to claim George Prevost played petty politics.]
By the time the attack on York happens, the battle at Presqu'ile is already over, although word takes a while to travel the distance. Immediately on hearing of the attack on York, Brock leaves the clean up at Presqu'ile to Procter and heads to York and then Kingston as fast as he can, arriving May 14. When he gets there, he finds Sir James Yeo who had just arrived the week earlier (one week earlier than OTL). Yeo is furious that he just missed the naval battle at York, and the two of them discuss with Dacres (and Prevost) just what needs to be done now. It is decided that as long as Sackett's Harbour exists as a US base on Lake Ontario, that British control will be threatened, and they should see what they can do about it. (OTL, Prevost (of all people) decided to strike at Sackett's while the US forces were attacking Fort George – which doesn't happen ATL).
Now Prevost had had as many as 4000 men at Kingston (OTL numbers), and Brock is moving some west. So by the time that Brock and Yeo have assembled the necessary shipping (including repaired and partly repaired ships from the Battle of York, but also bateaux and some of the salt boats and barges the US moved men TO York on), they have 4000 men they can take, while leaving Kingston defended. They sail for Sackett's on the evening of 27 May. The American forces on the lake being heavily reduced, there is no spy boat waiting to run off to Sackett's to warn them. So when the Brits arrived just after noon on the 28th, it was to almost total surprise. The Brits started to land, creating a beachhead and then moving in toward the harbour. Meanwhile there was great confusion in the town, because the people expected (militia) Brigadier Jacob Brown to lead them, but he wanted to pass it off to a Colonel of the regular army who was present. After some discussion, Brown did take command, but precious time had been lost and what might have been forward defensive lines were never held. Still, Sackett's Harbour held 2000 men who had been gathered for an attack on Fort George (which never happen iTTL), and there was fierce resistance. The initial line of militia broke and ran, and kept running when the British regulars formed line and marched and poured fire into them, but the American regulars formed line, and while they had to retreat under superior numbers, held their line and behaved professionally. When Brown sees his militia fleeing, he comes up with a stratagem – he sends cavalry out around announcing victory and rounding up some of the fleeing soldiers. Of course, some of them run into the British cavalry or advanced scouts or Indian patrols – and when the cavalry officer announcing 'victory' is shot out of the saddle by an unseen gunman, it really doesn't inspire confidence. Still he gathers enough to form a new attack column.
Meanwhile, Brown sees a column of smoke from the centre of town. Fearing an envelopment, he sends to find out what it is and discovers a naval lieutenant has started burning the ship on building stocks and naval stores, having decided the day was lost and that denying the matériel to the Brits was his job. Prevost, who's along for the expedition sees Brown's new column approaching and tries to order a retreat. Brock and Yeo gently point out to him that they are in charge, and his ADVICE, while gratefully received, will not be followed. The fighting is not finished by night fall, so both sides bivouac with strong guards around. However, since the fighting takes up most of the available men on the American side, there aren't enough to control the fire at the navy yard, which rages out of control, and sets the town on fire. In the morning, at first light, the battle resumes, and the British have a much easier time of it because so many Americans were either 1) fighting the fire all night, 2) fighting the fire right now, 3) ran off to retrieve their goods and family to get them out of the way of the fire (and/or fighting), or 4) were just demoralized by the whole chain of events.
The British require the American soldiers to gather in a group under guard, and won't let them go fight the fire (which by now has mostly died down, but there are still smoldering embers that could restart the blaze). Many of the locals are very resentful of the invading British, seeing them as responsible for burning the town (and indeed, that is the version carried by newspapers across the States). As British patrols go through (what remains of) the town and the surrounding country side looking for stores and weapons, they are occasionally fired upon by a gunman in hiding. This, of course, makes the British less friendly, and less willing to follow the rules themselves.
The British demand that all guns in the area be turned in, and start sending out patrols to enforce this. Any male caught with a gun is treated as an enemy combatant, and thrown into the guarded compound. Any one caught actually shooting at the occupation forces (or caught and blamed for such a shot) is summarily executed. They briefly consider shooting hostages for every British soldier shot, but they discard the idea. This time. They also unleash the Indian scouting contingent, telling them that any armed American left in the woods is fair game. They also stop handing out punishment for looting.
It takes a bit of time for the Brits to remove the cannon from the forts and ashes of the storehouses, and blow up the forts into uselessness. The last patrols through the area remove any all the food they can find, bringing it into a central site. They finish burning the town, and trample growing crops (trying to implement a scorched earth policy to prevent the US from successfully using Sackett's Harbor as a base again). Then they prepare to leave.
They assemble all the civilians and give them a handful of choices. 1) stay there, with 7 days rations, 2) be dropped off at Oswego to let the US care for them, or 3) (in the case of young women, mostly, but also mothers with small children) go to Canada with the returning flotilla. The protection of the RN and the army is, of course, only guaranteed in the last case. (The motives in the case of the last group are slightly mixed – especially in the case of the single women. However, the main motivation really was protection of the innocent. The story that circulated in the US didn't mention the mothers with children, and hinted or even stated base motives for the offer.)
Firstly they drop off the civilians at Oswego. In some ways, the British leaders would have liked to attack Oswego about this time (before they have time to bring in any more reinforcements or increase the defenses), but with the flotilla ferrying various people in various directions and with a sizable chunk of the army needed to watch over the prisoners, and prevent the civilians who stayed from trying something rash, their resources available would be rather iffy. Moreover, they'd then have to deal with all the civilians (the ones they promised to transport to Oswego) as just leaving them in ruined Sackett's Harbor would have been to condemn them to abject misery, at best. So, they say to themselves 'Oh well, can't be helped', and just drop off the refugees. Mind you, they do get a chance to spec out the harbour and defences at Oswego, which makes them feel a bit better.
The next task is to take the 'innocents' who wish it off to Kingston.
Then they deal with their prisoners. This is a real problem, because they've already being accumulating prisoners of war faster than they can really cope with them, and now, they have over 2000 in a single group. [While there were only 2000 soldiers at Sackett's Harbor when they arrived, and some were killed or escaped, the numbers are more than made up by the 'armed combatant' civilians.] In a normal war, they could engage in prisoner exchanges, but here there have been so few British prisoners taken that that doesn't relieve the burden much. Note that the naval yard workers, even if not armed or formally part of the army, were rounded up with the military prisoners.
Those prisoners with certain useful skills (especially the boat builders), and who wish to work on parole are permitted. Many of the boat builders absolutely refuse to work on war ships for the British, but some are convinced to work on commercial craft. More are willing to bend a bit and work on those commercial craft after they've been in the PoW camp for a while.
The prisoners are stored for a while in PoW camps, which are crowded and muddy and not as sanitary as it might be, while Prevost and company try to figure out how to handle the mess. Finally, they find an island they can dump the prisoners on. Let them grow some of their own food, isolate them, so if they do escape off the island, they'll never make it back, and guard the shores with light forces. Drop food off about once a month until they can get garden plots growing. Drop off more prisoners as they're accumulated in battle. Of course, a goodly number will escape off the island, but most won't survive in a hostile land, and if a very few make it back to the States, it's not such a big deal.
The Americans call this solution 'Devil's Island' and 'an extermination camp'. In fact, it represents the Brits' best effort at a humane long term solution. While the death rate (from various causes) in the camp is much higher than if they were living at home, it is a lot less than if they were stored on prison hulks where many French PoWs are stored back in England. So, once again, the British are doing their best, and are being vilified for it.
Meanwhile, navy Lieutenant Melancthon Woolsey is feverishly trying to prepare the defences of Oswego. It's not a great port, but now it's all the US has on Lake Ontario. And now he's saddled with hundreds of hungry civilians he has to deal with. Some of them, the more able-bodied, are put to work on building defences, but he sends most of them inland, up the Oswego back to civilization. It's hundreds of miles before they get to any major settlement, and many of the weak, infirm and the smaller children never make it. Once they do get to e.g. Albany, the government doesn't really know just what to do with them and many of those who survived the trek inland don't survive the coming winter.
Woolsey, of course, in addition to trying to build up the defences of Oswego, also wants to reinstate Sackett's Harbor as a port. But the only good way to do that is to send supplies by water in small boats, and the Brits have left a schooner to travel up and down the coast specifically to prevent that. After losing several loads of men and supplies, he gives up. For now.
As for the civilians left at Sackett's Harbour, they suffered various fates. Some few had farms or family outside the radius of British patrols and only suffered poverty and some hunger. Others, with farms within the patrol area were able to stay and survive if they had been cleverer at hiding enough food than the patrols were at finding it. But over half tried straggling through the woods back to 'civilization', and while many managed to do it, they were in such a piteous state that they often died shortly thereafter.
Very many of the civilians this group wished they'd chosen evacuation to Oswego, and the mothers evacuated to Oswego often wished they'd thrown in with the British.
New York state is enraged the disaster, and raises 5000 more militia to retaliate. Of course, there really isn't any way TO retaliate at this point. They end up cutting roads and paving them with logs all the way into Sackett's Harbor, both from the south and from Oswego. However, rough road transport like that makes a VERY long supply line, and while they end up being able to surge some thousands of militia up the road, they really can't supply them for extended periods of time, and getting e.g. cannon up such a road is ... no fun.
The end result is that whatever the US builds up in Sackett's Harbor during the war gets ripped down by the Brits when the protective force has to be withdrawn. While the US never formally abandons Sackett's Harbor, the effort becomes perfunctory after a while. Oswego stays a viable base for now, however.