In the evening of June 11, Lieutenant-General U.S. Grant sent a dispatch to Major-General Benjamin F. Butler, commanding the Army of the James on the south side of the James River. In part, that message read:
The movement to transfer [the Army of the Potomac] to the south side of the Jame River will commence after dark to-morrow night. Colonel Comstock, of my staff, was sent specifically to ascertain what was necessary to make your position secure in the interval … and also to ascertain what point on the river we should reach to effect a crossing…. Colonel Comstock has not yet returned, so that I cannot make instructions as definite as I would wish….
Grant went on to detail the proposed movements, starting with the Eighteenth Corps to move its infantry by boat. That corps trains and the balance of the army to march across the Chickahominy at Long Bridge, and thence across the James. Grant had already issued orders to Major-General George Meade, commanding the Army of the Potomac. And Meade already had orders ready for the corps to move. Keep in mind the intricacy and sensitivity of this move – the Army of the Potomac was to disengage on an active front, march dozens of miles across unsecured ground, cross a major river, and then reform south of the James preparing to give battle. And all that with the trains trailing along. A long haul:
But, as Grant indicated, on June 11 there was no point fixed where the bulk of the Army of the Potomac would cross the James. Details to be worked out, as he instructed Butler:
I wish you to direct the proper staff officers, your chief engineer and chief quartermaster, to commence at once the collection of all the means in their reach for crossing the army on its arrival. If there is a point below City Point where a pontoon bridge can be thrown, have it laid.
Brigadier-General Godfrey Weitzel was the Chief Engineer of the Army of the James. Weitzel had just completed a survey of the defenses along the James in the Bermuda Hundred sector, but now shifted his attention to facilitate the planned movement:
June 12, in anticipation of the crossing of the James River by the Army of the Potomac, I sent Lieutenant Michie, U.S. Engineers, to examine the river in the vicinity of Fort Powhatan to get all information on the subject. He reported the width of the river at the three points (A, B, C) to be, respectively, 1,250 feet, 1,570 feet, 1,992 feet; that the two approaches on the east bank at A would be from an old field across a marsh 1,000 yards wide; at B over a marsh about 800 yards wide; from these a spit of sand and gravel bordering the river from the bridgehead, averaging about forty feet wide and easily made into a good roadway sufficient for the passage of two columns of troops.
Lieutenant Peter Michie is no stranger to readers. The previous summer he supervised construction of the Left Batteries on Morris Island. Major-General Quincy Gillmore brought Michie north with the Tenth Corps. (A good selection if I may add.) The map below demonstrates the four possible crossing points surveyed by Michie and mentioned by Weitzel:
Weitzel went on to describe other preparations to support the crossing:
On the west bank the approaches to the two first were already prepared, leading by gradual ascent to the bluff on which Fort Powhatan is situated. It would require, to make approaches to the third, the clearing away of trees, making a ramp of one-third leading to the field above, the filling up of ruts and gullies and making a roadway to the Petersburg and City Point road. In consequence of these facts, I telegraphed to Lieutenant-Colonel Comstock, senior aide to General Grant, that if the passage was to be made here I would only require, at the farthest, previous notice of thirty-six hours to have the approaches for the bridge ready.
Grant had a crossing point.
Now came the difficult work – getting the army to the crossing point, laying pontoons at the crossing point, building and improving wharves, and improving the road networks. 150 years ago this day, the Federal engineers were coming to the fore… again.
(Citations from OR, Series I, Volume 36, Part III, pages 754-5; Volume 40, Part I, page 676.)