Robert E. Lee thought the Kelly's Ford attack was more than a cavalry skirmish; he thought it was the first step in a campaign by Hooker. He ordered Longstreet back to his side, only to countermand the order a day later when he discovered it was only a raid. In that time Hood's division had approached to within 45 miles of Fredericksburg. This prompted Lee to believe that Longstreet's men could return to the army rapidly in case of an emergency. After the Kelly's Ford fight, Lee discovered that the Ninth Corps was actually preparing to board steamers to head north, eventually to take a train heading west to Kentucky. Instead of recalling Longstreet, he had his "Old Warhorse" continue to forage.
In March, Lee began to take ill, first with a heavy cold then with chest pains. During this period his control over Longstreet's corps slowly slipped away. Also foraging in southern Virginia and North Carolina was Maj. Gen. Daniel Harvey Hill. Hill laid siege to a couple of towns, and while he didn't take any captives he did capture large quantities of food. Longstreet moved into southside Virginia, south of the James River and west of Suffolk. With Hill as his model, Longstreet laid siege to Suffolk in order to pin down the Federal garrison and take the town's supply cache. This created a dilemma. Longstreet needed to lay siege in order to secure supplies in the region but getting involved in a siege meant he was not free to join Lee if trouble occurred. He was now 130 miles away from Lee, requiring about a week's travel to join up with the main body of the army. The only benefit was that Longstreet's men were self sustaining with respect to food.
Lee didn't seem to be overly worried about Longstreet being so far away. He was becoming overconfident. He didn't have much respect for "Fighting Joe" Hooker's abilities (he wrote of him derisively as "Mr. F. J. Hooker"). Lee expected to fight a purely defensive battle. His army was situated at Fredericksburg, site of the Union's worst defeat to date. From reading Northern newspapers, Lee knew that in the past other Union generals — particularly McClellan — continuously over estimated Lee's strength. Since his own army was in a very strong defensive position and he believed the Union would overestimate the size of his army, Lee had reason to be confident. He had no way of knowing that Sharpe and his Bureau of Military Information (BMI) was providing very accurate estimates of the size of the Confederate army. Lee's own spies gave him what turned out to be a fairly accurate count of Hooker's total command at around 150,000 men, but Lee thought this was exaggerated, putting the number closer to 90,000.
There was something else Lee gleaned from Northern newspapers. A good portion of the Union army was due to muster out of service. In 1861 New York and Maine enlisted men for periods of two years. Some 35 regiments were due to muster out between April and June as their terms of enlistment came up. Another 25 regiments from Pennsylvania and New Jersey had signed up after the defeat at Second Manassas to terms of nine months. They, too, were about due to leave the army. Lee felt sure that Hooker wouldn't do anything until these troops had been replaced with new conscripts.
Lee prepared for an offensive of his own. He would have to stockpile supplies first, but once that was done he expected to move into the Shenandoah Valley and Maryland, taking the war north. He expected Hooker to remain defensive, shielding Washington. He ordered two cavalry brigade commanders, William E. "Grumble" Jones and John D. Imboden, to raid the Union's vital Baltimore and Ohio Railroad. Fitzhugh Lee would raid into the valley as well, as would John S. Mosby's partisans. In overall command of the cavalry was Jeb Stuart, who's headquarters was more than 20 miles away in Culpeper.
Hooker was also thinking about the two year men and the nine month men. His take was the opposite of Lee's. He believed he needed to launch an attack before he lost those regiments. There was widespread belief that soldiers that close to leaving would not make good fighters, so Hooker moved many of the regiments back to guard his supply base at Aquia Landing. This had the dual job of moving some of the men out of the way while protecting a very tempting target.
Hooker's plan was to force Lee out of the defensive positions behind Fredericksburg. Lee's biggest weakness was his supply line. Sharpe's Bureau of Military Information had informed Hooker of Lee's precarious supply situation. If the Richmond, Fredericksburg, and Potomac's rail lines were threatened, Lee had no choice but to deal with the threat or retreat to Richmond. Hooker ordered Stoneman to move west, then south, then east into Lee's rear. He was to move quickly, decisively and audaciously. The rest of the army was ordered to pack food for 8 days, and prepare for marching. One brigade from Howard's Eleventh Corps was moved to cover Kelly's Ford.
As Stoneman received his orders on April 13, Butterfield planned something of his own. The BMI had informed him that they had cracked the Confederate's simple signalling cypher. At the same time, they discovered that their own cypher had been cracked by the Confederates. Butterfield made use of this. On April 14 he sent a signal stating that Stoneman's intentions were to move to the Shenandoah Valley to deal with "Grumble" Jones. In passing he would take on Fitzhugh Lee. This signal was sent ostensibly to nearby units so that they could aid Stoneman. Sure enough the intercepted signal was sent to Lee, who in turn ordered Jones and Imboden to continue their raid but without Fitzhugh Lee's supporting raid.
Stoneman, though, was slow to move in spite of Hooker's orders. On April 14 he spent the daylight hours on an elaborate scheme for crossing the Rappahannock at four widely separated points. At Kelly's Ford and Rappahannock Bridge he produced noisy demonstrations while sending Brig. Gen. Benjamin F. "Grimes" Davis' brigade across the river at two fords far upstream. Davis crossed, but the light was gone before Davis could get to the other crossing points. That night it rained, the beginning of a downpour that lasted 24 hours. The rain came from the west, resulting in the Rappahannock rising some 7 feet as the headwaters made their way downstream. Davis was forced to move back across the swollen river, losing twenty five men to capture while several others drowned in the attempt. Stoneman moved north and west of Kelly's Ford, camping near Rappahannock Station.
Butterfield's message turned a major setback into a successful deception. Instead of figuring out Stoneman's true purpose, Lee believed that Stoneman was headed for the valley but had been stopped by the weather and Confederate cavalry movements. Mosby was moved further north and west to watch out for Stoneman and to raid Stoneman's force as it proved practical.
Hooker needed two days of clear weather for the roads to dry up and the rivers to drop. The rain kept coming. Hooker revised his plan, and looked upriver to Banks Ford and US Ford as crossing points for his infantry. He still intended for Stoneman to continue with his mission, but now he would cross with his infantry in support of cutting off Lee's communications. These fords were the focus of Burnside's Mud March operation and were well guarded. Rifle pits and gun emplacements would make a crossing there perilous. Hooker had quite enough of perilous frontal assaults. There were, however, two fords even further up stream. Hooker now began to devise his third plan of attack.
Lee's worries over Stoneman and his subsequent cavalry movements had created a 20 mile wide gap between his cavalry and his infantry. Within this gap sat Kelly's Ford. Hooker's plan was to send three of his corps as a "flying column" on 8 days rations up along the Rappahannock to Kelly's Ford. They would then cross the Rapidan and converge at a crossroads called Chancellorsville (named, ostentatiously, after a 2 1/2 story tavern and inn known as the Chancellor House). He would also move two corps across the river below Fredericksburg as a diversion while sending Stoneman back on his mission to cut Lee's supply lines. It was a bold plan that relied on in depth intelligence and total secrecy. The intelligence came from Hooker's Bureau of Military Information, supplemented by aerial reconnaissance from two hydrogen balloons. In order to maintain secrecy he didn't let any of his corps commanders know what was happening. If his troops didn't know the plan, Lee couldn't learn it from captured prisoners or Northern newspapers.
On April 27 Hooker moved out his "flying column". It had to move quickly, so the corps commanders were ordered to leave their artillery and most of their baggage trains behind, while mules carried ammunition. The individual corps making up the "flying column" were chosen based on the need for secrecy. Since moving men from the river bank would have alerted Lee's pickets, Hooker had to use the corps furthest from the river. These were Meade's veteran Fifth Corps, Howard's Eleventh Corps and Slocum's Twelfth Corps. The Eleventh and the Twelfth were not the men Hooker would have preferred. These were the two smallest corps, at about 11,000 and 13,450 respectively. In the Eleventh Corps, the large number of German immigrants were not trusted by the other men in the army or even their own corps (they were called, as a racial slur, "Dutchmen", derived from "Deutsch" or German). Both of these corps had a large number of men seeing combat for the first time. There were also regiments due to be mustered out in the coming weeks who were not left behind at Aquia Landing. Within the three corps about one quarter of the almost 40,000 men (not counting regiments already mustered out, or the artillery men left behind) were either going to battle for the first time, or they were nine month or two year men who were expecting to soon leave the army.
The Eleventh corps took the lead, followed by the Twelfth, then the Fifth. They arrived in the vicinity of Hartwood Church that night. Mosby's scouts, the men who would normally have discovered this movement, were miles away; Hooker's men had moved without being discovered. The next day the Eleventh started off in the lead again. This corps was slower than expected because Howard had allowed his full baggage train — 5 times the size Hooker had ordered — to accompany him. Hooker dressed him down for it. In spite of the train Howard arrived at Mt. Holly Church, near Kelly's Ford, at 4:30 p.m., only half an hour behind schedule. There, pontoon bridges delivered the long way around via Washington, were waiting. The pontoon boats crossed at 6 p.m. and the Rebel pickets were swept away. The bridge was laid by 10:30 p.m. and the Eleventh Corps began to cross.
On the 28th, two divisions of Couch's Second Corps moved up to Banks Ford in secrecy. On the 29th they advanced on US Ford, repairing the road as they went. There they waited, expecting Meade's Fifth Corps to capture the other side of the river crossing the following day.
Jeb Stuart heard of infantry crossing the river at 9 p.m. on the 28th, but the telegraph route back to Lee, via Richmond, contained at least one station that was closed for the evening. Lee wouldn't receive word of the crossing until the next morning.
Also on the 28th, Reynold's First Corps and Sedgwick's Sixth on the extreme left of the Union lines below Fredericksburg moved towards the river, hiding behind the heights overlooking the crossing points. On the morning of the 29th these two corps crossed in the fog, achieving a bridgehead on the Rebel's side of the river. They pushed the Confederates out of the forward rifle pits and held the ground between Franklin's Crossing (the area where Franklin's men crossed during the Battle of Fredericksburg) and the river opposite Hamilton's Crossing. Reynolds wanted to advance into the attack, but Hooker's orders were clear: he and Sedgwick were to occupy the bridgehead and not advance.
On the morning of April 29, the flying column advanced from Kelly's Ford. The Twelfth Corps was moved into the lead and headed southwest towards Madden's Tavern, then from there moved eastward to cross the Rapidan at Germanna Ford. The Eleventh Corps followed. The Fifth Corps took a different route. They headed southeast from the ford and marched straight towards Chancellorsville. The Fifth Corps crossed the Rapidan at Ely's Ford by 10 p.m. The columns were covered by a single brigade of cavalry under Brig. Gen. Alfred Pleasonton. The rest of the cavalry were taking part in Stoneman's raid.
Stoneman's cavalry finally arrived at Kelly's Ford at 5 p.m. on the 29th. Though he told Hooker for days he was ready to advance, he didn't begin making plans until he received word from the commanding general on the 28th. As such, when he arrived at the ford he had to wait for infantry to clear before he could move across, as they had priority. That night he only made it as far as Madden's Tavern, barely 4 miles from Kelly's Ford. If he had been more aggressive, he could have bumped into Stuart's command and kept it apart from Lee.
Lee received Stuart's message about troops crossing the Rappahannock on the morning of the 29th. Lee had telegraphed Richmond to have them send Longstreet to join him, but there was no way Longstreet would be able to retrieve his baggage train and extricate himself from the siege of Suffolk in time to join Lee. Lee wasn't sure of Hooker's main thrust. The crossing at Kelly's Ford could be infantry accompanying Stoneman's cavalry, intent on raiding the Confederate supply line, in which case the assault below Fredericksburg was the main assault, a rematch of the December battle. This seemed likely to Lee, but he wasn't sure. Lt. Gen. Thomas "Stonewall" Jackson wanted to push the Yankees below the town back across the river but Lee suggested otherwise. The crossing was under cover of massed artillery on Stafford Heights and Jackson stood to be torn apart even if the Yankees were driven back across.
The men of Maj. Gen. Richard Heron Anderson, one of two divisions in Longstreet's corps left behind for Lee, held the Confederate extreme left flank. On the 29th Lee ordered them to take up positions at Chancellorsville in case the Union forces crossing up river fell on the army's flank. Anderson moved his troops to the intersection of the US Ford Road and the Orange Plank Road. The other division left by Longstreet, that of Maj. Gen. Lafayette McLaws, was moved to the area of Marye's Heights. This was the site of the bloodiest carnage during the Battle of Fredericksburg.
Stuart, meanwhile, had captured prisoners and now knew Meade's corps had crossed the Rappahannock. Once again he telegraphed Lee. This time his report would give Lee the information he needed to determine which advance was the main thrust of Hooker's campaign. Once again, the report sat in a telegraph station over night.
Artillerist and diarist Porter Alexander would say of Hooker's operation, "On the whole I think this plan was decidedly the best strategy conceived in any of the campaigns ever set on foot against us."
On the morning of April 30, in the clear light of day, Richard Anderson didn't like the position he had chosen for his men the previous evening. There was little room for artillery and the visibility in the woods was poor. Using discretion in Lee's orders, he moved his men 3 1/2 miles east to a more open area near the Tabernacle and Zoan churches. There would be no fight for Chancellorsville on April 30.
At about the same time the three Union corps of the "flying column" advanced towards Chancellorsville. Meade's corps marched out at 4 a.m., and his lead troops arrived there around noon. Along the way, his corps uncovered the crossing point of US Ford. Bridges were laid and the troops of the two divisions of Couch's Second Corps began to cross. Meanwhile, Sickle's Third Corps followed the route of Couch's men, advancing on Banks Ford. Couch's and Sickle's corps would add more than 30,000 men to the flanking column once they were across the river.
Slocum joined up with Meade in mid afternoon. Meade suggested they advance from Chancellorsville. Slocum, in command of the Union right wing while Hooker wasn't present, told him they were ordered to stop there and make the place defensible. The Army of the Potomac converged on Chancellorsville.
Hooker's decision to halt at Chancellorsville would come under criticism after the battle, but it was based on sound intelligence and adhered to his plan. He wanted to engage Lee in a defensive battle after first cutting Lee's supply lines. He had stolen a march on Lee, but so far there had been no word of Stoneman cutting Lee's line of communication. The conditions were not quite ready for a battle. That evening Hooker would state in an order that, "...our enemy must either ingloriously fly, or come out from behind his defenses and gives us battle on our own ground, where certain destruction awaits." So far everything was going according to his plan.
Lee, for his part, spent the day trying to figure out Hooker's intentions. Jackson wanted to assault the bridgehead below Fredericksburg, but Lee suggested that he look at the situation closer before commiting troops. Lee rode off to Anderson's division while Jackson studied the matter. After surveying the far left of his line, Lee decided that the true attack was coming from Hooker's "flying column". He moved a powerful force to match it. He had McLaws leave behind one brigade (McLaws chose Barksdale's Mississippians) to defend the town while the rest of his division was to march to the west. Jackson was to move his entire corps west, except for one division to block Reynolds and Sedgwick. Jackson chose Jubal Early's division to stay behind. That night, Jackson's corps and McLaws division marched to counter Hooker's force on the Confederate left flank.