To those of you expecting to find a timeline I'm afraid I must dissapoint you as this is one of my abandonned ideas - of which there are many - but its one I'm quite fond of so I thought I'd share it with you.
A while ago I discovered attempts by at least two high profile Confederate Generals - Joe Johnston and A.P. Hill - to convince George McClellan to join the Southern cause and this led me to explore, in very vague terms, what the war would be like with McClellan in grey and where he could be of most use.
I decided that it would probably be best to keep him away from field command if I wanted him to be around for any real time in a position of authority - since he's bound to fall out with the Confederate higherarchy sooner or later - but this left me with very few options of where to put him and only one glaringly obvious one - New Orleans.
I imagined a scenario where upon resigning as an officer in 1857 McClellan undertook work as a civilian engineer in Louisiana and eventually was employed to inspect the defenses of New Orleans and suggest improvements. As the 1850's come to an end McClellan is still employed in engineering work around New Orleans and once the elections of 1860 end he is approached by many trying to discover where his loyalties will be.
During this time McClellan has become isolated from the North and found new friends in the South and is particularly close with John T. Monroe - mayor of New Orleans - and Thomas Overton Moore - Governer of Louisiana - who get drawn into McClellan's cult of personality and comes to greatly admire him.
When Louisiana secedes from the Union Monroe offers McClellan command of New Orleans. McClellan accepts the offer and becomes commander of the Military District of New Orleans, a Major-General of the Louisiana Militia.
McClellan rises to prominance in the months following secession for his excellent work as a trainer and administrator in New Orleans and Jefferson Davis - who still becomes President of the Confederacy regardless of McClellan's presence in the South - contemplates sending him to Sidney Johnston in Tennessee but opposition from Monroe, Moore and the Louisiana Senator Thomas Jenkins Semmes prevents this - McClellan is kept ignorant of Davis's contemplations.
Davis also attempted to get men and weaponry diverted from New Orleans to Virignia and Tennessee but was forced to back down following opposition from McClellan, Monroe, Moore and Semmes - allowing the City to keep hold of some artillery pieces which would have been sent elsewhere otherwise.
When Sidney Johnston loses an army at Fort Donelson Davis attempts to get McClellan to go north to link up with Johnston but McClellan refuses to serve under him and raises complaints to Monroe, Moore and Semmes about interferance in his command making his job impossible. They object and Davis backs down but with growing discontent about McClellan's attitude.
Throughout 1861 McClellan devotes himself to completing improvements to the defenses of New Orleans and to training as many troops as he can - a task which includes raising units himself, conscripting men into his district and divert troops meant for Tennessee or Virginia to New Orleans - the result of which is that as 1861 turns into 1862 the City has some fomidible but unfinished walls and earthworks and a force of some 6-7,000 men within the citis defenses and artillery.
When Farragut attempts to move on New Orleans and take the city McClellan - with Mansfield Lovell as his main subordinate - manages to drive him away gaining the nickname "Lion of New Orleans" from Monroe in the process - which was more than likely an exaggeration of praise on Monroe's part.
During 1862 New Orleans becomes a major trainin center for troops as well as the scene of several defeated Federal attempts to seize the city. McClellan benefits greatly from the arrival of Richard Taylor who ends up leading the defense of the city while McClellan argues with Davis and the Presidents representatives and begins to alienate the politicians in Louisiana as his ego begins to swell - yet McClellan gets the praise instead of Taylor.
McClellan demands a tranfer to a field command in the Spring of 1862 - maybe to the Army of Mississippi if Shiloh happened and went as OTL or to the Army of Northern Virginia if that theatre went as OTL, I never really figured out what happened elsewhere while creating this - but is turned down in favor of men closer to Davis personally like Bragg and Lee. As such McClellen increasingly grows to see his appointment to New Orleans as a military exile and is not slow in voicing his discontent.
And that is all I have. I simply cannot continue it no matter how I try - historical and geographical ignorance on certain points render some of my ideas impossible no doubt - but I still enjoyed coming up with this.