I'm thinking Infantry most likely will remain at 1 movement, Skirmishers might be all-terrain as roads or 2 movement, Cavalry will be either 2 or 3 movement (2 if the ACW railroad way, 3 if I can do a hybrid of ACW and Civ3).
Infantry in general marched about 12-15 miles a day, on a forced march they could cover almost double that. 1 movement point preserves this realism, and keeps the tactical battles intact.
Railroads I'm still trying to decide how I want to do it, if its the ACW way then they will be most likely 1/5 of a movement point. I'm hoping though to make Railroads a hybrid between ACW and normal Civ3 railroads.
Naval movement will be drastically increased (probably tripled to quadrupled).
Cities in the Mid-Atlantic (New Jersey, Pennsylvania, Maryland, Delaware, eastern Virginia), southeastern NY, along the Buffalo-Albany corridor, and New England will be heavily concentrated, to illustrate that this area in general was either highly urbanized, or has alot of Civil War significant cities (like Gettysburg and Urbana).
Cities in the South and in the Midwest will be spaced much further apart on the whole.
I'm also going to try to fit places like Shiloh, which was a very important western battle fought in 1862. Middle/southeastern Tennessee also will have more significance, with Tullahoma, Murfressboro, and Franklin possibly all in at once. As I said, the larger map is going to allow for ALOT more to be put in, enhancing realism.
With regard to Gettysburg, the following cities are near it:
Harrisburg, PA
Chambersburg, PA
York, PA
Frederick, MD
Hagerstown, MD
York and Chambersburg figured directly in the battle, while Frederick was passed through by both forces on the way up. Harrisburg was Lee's ultimate objective.
I've completed this area of the map with regard to cities now.
Also, the Shenandoah Valley will have several cities in it (not sure which yet, haven't gotten that far west into VA yet). In ACW, its just represented by Staunton and Winchester (at either end).