"Lee is free to loot most of Maryland and South-Central Pennsylvania of everything that isn't nailed down. Mac only moves enough to prevent Washington's fall"
The only real question is whether Lee is comfortable enough accepting Mac as being that much of a slug. It's obvious in hindsight, but is it realistic to accept it at the time? Again, I believe the whole incident was a trap that was messed up. Hindsight says Lee is reasonable free to do as he pleases while plundering/rejuvenating his troops. Contemporary thinking says you cannot leave a foe on your flank.
I would only say that Lee was not only phenomenal at getting inside the heads of his enemies (when his best cavalry was around), but that he was never better at it than with McClellan. And as long as your opponent believes you are two to three times the size of the AotP


, then you know he won't take any risks whatsoever.
Still, IF Lee gets to wander around at will, I don't think you can change major factors and still get back to the same conclusions in your ATL (emanc proc in reasonably same time frame). the end of the war may be the same (or it may not), but how you get there is going to be much different.
Actually, it was SecState William Seward who insisted to Lincoln that the EP not be issued until after a major strategic victory was scored by the Union, and at the time the political sense was that the Union was NOT winning the war. That the EP would be seen as the last shriek of a defeated foe pleading for a servile insurrection as the only means of Union victory. So the only way the North could win was through the actions of Southern slaves.
Even IOTL, Antietam was seen by Lincoln as a "moth-eaten victory", just barely sufficient to qualify as a means to issue the EP. Without Antietam, you'd be looking at either a major Western victory (which might not provide the gravitas needed politically) or else waiting for Gettysburg and Vicksburg, which would be far more effective to hit the South when they were down (converting a double whammy into a triple whammy!

).
The reason Turtledove can be summarily dismissed is because he would be torn to shreds here and on most alt history sites. He's a popular author, but his ideas are extremely flawed. At best you can argue 'hey, it's possible'. That doesn't make him the god of the alt history world.
You can say the same regarding the Gingrich/Forstchen Gettyburg trilogy. On no less than three separate occassions, you see forced contrivances to throw the AotP into pointless meat grinders, and always through the same tired means: insane levels of vainglorious insubordination (1).
Meade: "He's done WHAT!?" (half the AotP is ruined)
Sickles: "He's done WHAT!?" (2) (the other half is ruined)
Grant: "He's done WHAT!?" (3) (every last remnant is totally destroyed, leaving an amalgamation of odds and sods under the banner of a sole surviving unit, Sykes' V Corps)
1) Of course, that could NEVER happen with the incomparable AoNV.

Except for the throwing away of one division, Pickett's (who else?

).
2) It's been a long time since I've read that trilogy. It may have been another officer talking ABOUT Sickles.
3) Yeah, that same wornout phrase is in all three books. You would have thought the editors would have nixed that.
Lee runs around in Maryland and McClelland soon gets info that Lees force is divided anyone by loyalists and/or spies. He might actually do something better than attack Lee and that is to shadow Lee and always be south of Lee distrupting connections between Lee and the CSA
Yeah, but what about the CSA's 200,000 man army

that is still sitting in Northern Virginia, just waiting to catch MacClellan between two forces?

This is why I think that some future ACW "historian/conspiracy theorists" will make the case that Alan Pinkerton was either enjoying the favors of one of those Southern "ladies", or was an outright Confederate agent himself.


