No, the four citations and the primary sources I provided indicated it was Stuart's Raid around McClellan's entire army that motivated his shift. And I still expect your apology for saying "You have invented a change of base to the James" when you yourself conceded the change of base existed, though you persist in dismissing the repeated citations I've provided and the ones you provide nothing of, nor the context those citations appear in.
What "four sources"?
If I may quote you. Your first source was
http://americancivilwar.com/campaigns/Peninsula_Campaign.html which you quoted as:
"At this point McClellan yielded the initiative to Lee. With his line of communications to White House, his supply base on the York River, cut and with the James River open to the U.S. Navy, the Union commander decided to shift his base to Harrison’s Landing on the south side of the peninsula. His rear areas had been particularly shaky since Confederate cavalry under Brig. Gen. J. E. B. Stuart had ridden completely around the Union Army in a daring raid in early June. The intricate retreat to the James, which involved 90,000 men, the artillery train, 3,100 wagons, and 2,500 head of cattle,
began on the night of June 27 and was accomplished by using two roads. Lee tried to hinder the movement but was held off by Federal rear guards at Savage Station on June 29 and at Frayser’s Farm (Glendale) on the last day of the month.. "
The bolded part is mine. Your first source says he started to change base on the night of the 27th June.
Your second source,
http://www.almc.army.mil/alog/issues/Marapr96/ms809.htm says:
"McClellan began relocating his supply operation and shifting his tactical focus south of the Chickahominy River within a week of Stuart's raid. On 18 June, he ordered 800,000 rations shifted from White House to the James River. Colonel Ingalls, in charge of the White House depot, dispatched several loads of forage and provisions to the James on 23 June. Canal-boat and barge floating wharves on the York River were broken apart. Four hundred transports began shifting cargo from White House to the James.
In the meantime, Johnston had been wounded and replaced by Robert E. Lee as the Confederate commander. Lee counterattacked McClellan's army on 26 June, intent on driving the Union invaders away from Richmond. The ensuing Confederate offensive lasted until 1 July and became known as the Seven Days' Battles.
While struggling to repulse the attacking Confederates, McClellan began shifting his actual base of operations to Harrison's Landing on the James on the morning of 27 June. Contrabands were evacuated to Fortress Monroe on canal boats. Supplies not needed by the forces north of the Chickahominy during the switch of fronts were retrograded by wagon and rail to White House.
Van Vliet shipped supplies by wagon and rail to Savage's Station so advancing troops could resupply en route to Harrison's Landing. They destroyed excess stocks. Supplies at Orchard Station and Despatch Station were sent on to Savage's Station as well, and excess stocks were evacuated to White House. Some 2,500 cattle were herded across the Peninsula to the James.
Transports evacuated hundreds of sick and wounded. Cavalry screened the hospital while litters and ambulances evacuated the wounded. Gunboats (the Commodore Barney, Currituck, and others) stationed around the port complex at White House provided additional security. Commissary stores were evacuated by transports; the sutlers' supplies were looted by departing Union soldiers and advancing Confederates. Buildings, including White House itself, and rows of tents were fired with whiskey-soaked hay. Ammunition dumps that could not be evacuated were blown up-the sounds convinced Confederate leaders that a full-scale Union retreat was in progress. Three locomotives and a hundred railcars were also burned. When all was done, Colonel Ingalls, now deputy quartermaster for the Army of the Potomac, and his staff boarded the transport Circassian and sailed to Fortress Monroe.
Following the Union retreat after the battle of Gaines' Mill on 27 June, wagoneers loaded all the supplies possible at Savage's Station for retrograde; the rest were destroyed. Meanwhile, Stuart arrived at White House in time to see the last gunboat leaving and nine barges, five destroyed locomotives, trains of railcars, and rows of tents burning.
Lee and his chief subordinate, Major General Thomas J. (Stonewall) Jackson, were both convinced after the main battle that McClellan would hold his lines of communication with White House. Stuart therefore ordered Brigadier General Richard S. Ewell's cavalry to attack White House. The cavalrymen saw fully loaded trains being run into the river with engines at full steam to avoid being captured by the Confederates. The finale of the entire operation was, fittingly, unusual: Stuart's horse artillery traded shots with the Union gunboat Marblehead at the very end of the evacuation from White House. "
Again, the bolded part is mine and says he started to change base on the night of the 27th after the Battle of Gaines Mill. The movement of supplies from his base at White House onto ships was not a reaction to Stuart, but preparation to detach a force to take Balls and Drewrys Bluffs.
Your third source,
http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA328181 says:
"Though several of McClellan's division commanders recommended a thrust towards Richmond
through the Confederate weak right flank, he ordered his army to fall back towards a newly
established base of operations on the James River to gain the protection of Union gunboats.
Lee attempted to pursue, but a series of uncoordinated but successful independent delaying
actions by Union corps commanders allowed the supply trains to escape. The Union forces
then established strong defensive positions on Malvern Hill and shattered piecemeal
Confederate assaults. Despite inflicting heavy casualties, McClellan ordered the rest of his
army to move to the new base at Harrison's Landing. Following a stalemate there, Union
forces subsequently withdrew by ship to Washington."
This paper is terrible. There are no references backing up your quote. More to the point, it does not even touch on your argument and so must be ignored.
You repeat this with Miller, giving a quote that does not even touch on the subject in hand. You then quote McClellan:
"I decided then to carry into effect the long-considered plan of abandoning the Pamunkey and taking up the line of the James.
the necessary orders were given for the defense of the depots at the White House to the last moment and its final destruction and abandonment; it was also ordered that all possible stores should be pushed to the front while communications were open. "
Which agrees completely with my position and does not in the slightest support your position.
etc.
You're engaging in
argumentum verbosum, amongst other fallacies. None of your quotes actually support your argument that McClellan changed base weeks before Gaines Mill. You simply have no case.