I gave much thought to the subject at hand, and offer my opinion of the quality of Union and Confederate command:
Independent Command:
For Union high command, we have many generals who achieved greatness and failure. We have successful generals like Grant, Sherman, Thomas, Rosecrans, Curtis, Sheridan (ugh), Meade, Sam Curtis, and James G. Blunt.
Ulysses S. Grant stood out to be the best Union general in my book, displaying an brilliance in grand strategy, strategy, and operations (Vicksburg, Overland Campaign). In addition, Grant displayed flexibility and an incredible understanding of the mindset of politicians. To demonstrate, before Grant became Lieutenant General, Grant proposed a very radical strategy. Grant suggested that they abandon the lines of attack previously adopted against Lee, and try a new approach. Grant proposed landing 60,000 men at Suffolk, Virginia, and having them march into North Carolina, with their objective being to break the railroads into Virginia, and capture the city of Wilmington. Meanwhile forces would move through Western and Southwestern Virginia to eliminate lines of supply from that area. Effectively, Virginia would be isolated, and Grant believed Lee would be forced to fall back to defend his dwindling supply lines. From that point on, the Union would dictate the action, and Union naval superiority could be used to shuttle forces around. It was essentially a version of Grant's Vicksburg Campaign applied to the Eastern theatre. It was bold, aggressive, targeted enemy supply lines and logistics rather than armies, and meant the Rebels would have to dance to a Federal tune for once. What this plan shows is a skilled strategic and operational commander proposing a plan that avoided a direct confrontation with the main enemy army, and forced that army to react to his own moves, therefore seizing the initiative. When Halleck rejected it, Grant understood that the politicians demanded a direct assault onto Richmond, and promptly redrew his plans to capture Richmond. In terms of casualties the myth of 'Grant the butcher' is destroyed. Throughout Grant's career as a general, Grant inflicted about 184,000 casualties and suffered about 137,000 casualties; ironically, Robert E. Lee inflicted 220,000 casualties and suffered 210,000 casualties. I dare say, among all the generals of the American Civil War Ulysses S. Grant was the best of the lot.
Thomas was an excellent tactician and battlefield commander, he performed very capably as the commander of about 2/3rds of Sherman's infantry. In addition, he seemed to have displayed a fine understanding of operations, demonstrated in his suggestion to Sherman to seize Snake Creek Gap. However, Thomas never got the opportunity to demonstrate any strategic skills that he may or may not have had.
Strictly as a military strategist, Sherman can stand alongside Grant, and in theory, could have been as great a general-in-chief. However, Sherman could not stand political interference and greatly despised politicians and reporters. I admittedly find Sherman to be overrated in a few aspects, but cannot deny his brilliance in strategy and logistics. Operationally, Sherman handled the movement of his army very finely and did have good operational ideas. However Sherman does suffer several very severe flaws. Tactically, Sherman was very mediocre at best, he suffered disasters like Chickasaw Bayou, Kennesaw Mountain, and was incredibly careless at Bentonville. Sherman was also poor at using cavalry in general.
Meade does not receive enough credit as a commander, I will cite an old post as to what I thought about him:
Considering that Meade took over an army in the middle of a campaign, I would say he deserved a lot more credit than what he is usually given. During the first-twenty four hours of his command, Meade effectively concentrated his army, prepared an advance of over twenty miles the next day, and got the men started early, as well as making other preparations. Andrew A. Humphreys, Meade's future chief of staff and not an easy man to impress, stated, after discussing the difficulty of moving a great army, "I take it too that this army has never been moved so skillfully before as it has been during Meade's command".
After a grueling march the next day, Meade fanned out his army in a manner that protected his wings and let him concentrate the army in case of emergency. On June 30th, Meade learned that Longstreet and Hill were near Chambersburg, moving in the direction of Gettysburg, and Ewell was at York. Meade concluded that the Confederates would advance towards Gettysburg, and sent the II and III Corps to back up Reynolds. Meade assigned Reynolds temporary command of about a third of his army to watch the left flank, the point of danger. With Buford in position, Reynolds possessed good information about the enemy's movements.
Meade issued two important orders; one for a general advance on July 1st, in the direction of Gettysburg, and the infamous Pipe Creek Circular, which was a contingency plan for a withdrawal to a very strong position just across the Maryland border.
Meade definitely factored in Gettysburg in his plans; he sent I and XI Corps to the town, the II Corps to Taneytown but with the option of moving to Gettysburg or Emmitsburg as the situation dictated, the V Corps to Hanover, the III Corps to Emmitsburg, and the XII Corps to Two Taverns. Two corps to Gettysburg and four within supporting distance on roads that lead into Gettysburg.
In conclusion, I would say Meade had acted with prudence but sufficient boldness. Coddington calls Meade's movements and plans a beautiful strategic pattern.
Meade's pursuit of Lee after Gettysburg has received a lot of criticism, unjustly so in my opinion. Meade was constrained by the Lincoln administration's instruction to remain between Lee's army and Washington D.C. and was hampered by a serious loss rate in his corps commanders.
After Lee withdrew across the Potomac, Meade pursued, and came within a hairsbreadth of cutting off Ewell's II Corps at Manassas Gap; thanks to "Blinky" French, Ewell got away. Meade planned a fall offensive, but got preempted by Lee in the Bristoe Campaign; not wishing to fight in a position that offered him no advantages, Meade retreated to Centreville to avoid being flanked after a couple of engagements, including one where A.P. Hill got badly bloodied at Bristoe Station.
About two weeks later, Meade succeeds in surprising Lee at Rappahannock Station and Kelly's Ford, capturing two entire Confederate brigades at the former engagement, and crosses the Rappahannock.
Later that year, Meade began the Mine Run Campaign, a planned surprise attack through the Wilderness with his entire army on Lee's divided army, targeting the flank south of the Rapidan River. Once again, French's III Corps ruined Meade's timetable by getting bogged down in fording the river. Lee managed to withdraw to prepared fortifications at Mine Run; II Corps commander Warren concluded they were too strong to attack, and after taking a look for himself, Meade reluctantly agreed, and pulled back before Lee could counterattack, which indeed he was planning to do. Meade deserves more credit for than he gets is the decision not to launch a pointless and suicidal attack at Mine Run. In many ways, Meade's situation at Mine Run was a lot like Burnside's at Fredericksburg; he was making the last offensive move that could be made that year, and he was under enormous political pressure to at least appear to be aggressive. Despite the political consequences for himself, he had the moral courage to call off the attack and pull back, unlike Burnside a year earlier. He never received any thanks for it, indeed losing his independence as a commander entirely for his trouble, but he made the right decision.
Meade, on the south side of the Rappahannock at this point, wanted to winter the army in Fredericksburg; by doing so, he can avoid the Wilderness the next year, and advance on Lee in open terrain where his artillery superiority can be used effectively. Halleck refuses however, probably believing Meade won't be able to screen D.C. from Fredericksburg.
It's difficult to judge him too much on his role in the Overland Campaign; he was often more hindrance to help, but it's an open question as to whether anyone else could have done better in his frustrating role. I think that's why Grant never uttered a word of criticism about Meade's role in his campaign; having been in a somewhat similar situation under Halleck for a while, he had some idea what it was like to be in Meade's position (Siege of Corinth).
May 1864 must have been a very frustrating month for George Gordon Meade. Though he was still the commander of the Army of the Potomac, he had been growling as Ulysses S. Grant intervened more and more in the army’s operations. Nor was he pleased with the performance of Ambrose Burnside, who headed the independent Ninth Corps under Grant’s direction as a sop to Burnside’s seniority. Thus far Burnside has proved a disappointment in the field. Meade had predicted that if things went well, the press would laud Grant, while if things went badly, it would be Meade’s fault. After the Battle of North Anna, Charles A. Dana, the assistant secretary of war, read a telegram from William T. Sherman expressing the hope that Meade’s army would achieve the same successes thus far enjoyed by Sherman, Meade snapped. Sherman’s missive, he fumed, was an insult to his men and himself: the Army of the Potomac needed no one to tell it how to fight. As a result, Grant was going to allow Meade to direct the operations of his army.
The two major failures, that I can fault him for, are the Battles of Cold Harbor and the Crater. While I must put Grant at fault for ultimately being in charge of Meade, Meade was exercising tactical control at that time, and both Meade and the corps commanders failed to follow Grant's orders to examine the ground before launching an assault, and they failed in coordinating it. Meade bizarrely boasted about ordering the attack in a letter to his wife. Grant should have called off the assault earlier than he did once it was apparent nothing was going right, but it was Grant who stepped in to call it off while Meade was still urging his commanders to press the attack.
However, we have failures like Burnside, John Pope, Benjamin Butler, Buell, and Sigel.
I feel like John Pope is perhaps getting more of a bad rap then he deserves, per the second Manassas discussion. Everything he does for most of August 1862 is at least defensible, and he deserves some credit for being the first Union army commander in the East to use volunteer cavalry brigades; he was the first officer in the East to do so, and arguably none of his successors exceeded him here. The value of said cavalry was made apparent when Buford's men enabled Pope to escape Lee's first trap south of the Rappahannock. Where Pope really does fall apart is his refusal in the last phase of the campaign to accept information that he doesn't want to believe, but his experience up to that point had given him some basis for distrusting certain subordinates, and the fact that both Halleck and McClellan left him out to dry didn't help. As Jackson jumped the gun a bit at Brawner's Farm, Pope's overall strategy of rushing on Jackson before Longstreet could come up was not necessarily the wrong one, albeit his piecemeal attacks were foolish. At the end of the day, Pope did rise to the moment of crisis (which he was responsible for, admittedly) and fight his way out of the situation he had created, and then parried another attempt Jackson made to flank him at Chantilly. Pope reminds of Joe Hooker in that if you excise a couple of weeks, he had a good overall military record, and he died a respected major general in the regular army. Unlike Hooker, his problematic personality mellowed over time and he was trusted with important department commands near the end of the war and for decades afterwards. None of this to deny Pope performed quite poorly overall during the actual battle, but other Civil War generals were given considerably more latitude for their failures than he was.
Ambrose Burnside was never an impressive commander. As an army commander, he deserves credit for maneuvering Lee in the initial stages of the Fredericksburg, and was stopped only due to a failure by the Union War Department to provide him the pontoon bridges necessary to cross over to Fredericksburg. The idea that Burnside should have gone to other fords is rather silly as it ignores the fact that the lower Rapphannock fords (the path Joe Hooker took) were impassable due to the rain and any Union force that crossed the U.S. Ford would be completely isolated if the rain continued (As it turned out, the rain actually continued. Burnside was right about his decision not to cross there). By the time Lee got to Fredericksburg, Burnside should have admitted defeat and enter winter quarters or change his plans. However, Burnside lacked either the flexibility or moral courage to do so. In the actual battle of Fredericksburg, he performed poorly, failing in communicating the importance that Franklin was to storm the heights and thus dooming his own plans.
Butler and Sigel were both political generals that were incredibly inept at doing their jobs. As commander of the Army of the James, Butler's performance was a failure of epic proportions. By all means, the Confederate garrison at Petersburg should have been routed, and Petersburg be in Union hands while Lee and Grant were fighting it out in Spotsylvania Court House. Sigel did no better, getting routed at New Market.
Now for the Confederates, other than Lee, most of their army commanders were very lackluster. Uncle Joe is competent: he's particularly talented at organization; he got the Army of Tennessee back in shape after Bragg's disaster at Chattanooga and he was a fairly good judge of talent, he's partially responsible for the rise of Longstreet and Stuart, but can't get along with Davis and isn't one to seize the initiative. Beauregard is quite competent but highly erratic and has an even worse relationship with Davis. Bragg can't carry a good campaign idea through to fruition, practices cronyism, is a martinet, and absolutely cannot work with anyone. Van Dorn, Price, and Sibley were pretty much unmitigated disasters. Gideon Pillow was probably the least competent general in the entire war. Pemberton was more bureaucrat than soldier. Crittenden and Zollicoffer flunked one minor battle, with one of them dying in the process and the other pretty much vanishing into obscurity. Richard Taylor was actually quite competent and did a nice job during the Red River Campaign, he's probably second-best to Lee as an independent commander. Kirby Smith is something of an enigma; he directly commanded two tactical engagements. One of them was a crushing victory that routed his opponent (Richmond KY) and the other was a complete fiasco (Jenkins' Ferry.) He also ran what was virtually an independent subdivision of the Confederacy in the trans-Mississippi. Strategically I'm a little unsure about him. He also tends not to play well with others though; Taylor hated him, and Smith absolutely refused to cooperate with Bragg during the Kentucky campaign.
As for Robert E. Lee, on the campaign level, Lee is undoubtedly a superb strategist. While serving as Davis' military advisor, Lee actually devises the only plan the Confederates implement in Virginia that represented a reasonable use of the operational art with his usage of Stonewall Jackson's Valley Campaign to keep Union reinforcements from reaching McClellan near Richmond. Jackson of course, plays his part in Lee's vision perfectly here. Then, Lee further displays sound judgement at the end of the Valley Campaign; when Jackson wants to continue north and continue threatening Washington, as appealing as this might have sounded, Lee correctly judges that Jackson's diversion has served its purpose and brings his troops to Richmond in time to achieve near-parity with McClellan's forces for the Seven Days Campaign. The resulting campaign was not coordinated very well, but Lee's strategy plays out and McClellan is neutralized for the time being. Lee plans well and across a broad area, incorporating multiple forces, and seizes the initiative and does not relinquish it. On the minus side, new to his army, his forces don't coordinate terribly well during the Seven Days, and somewhat by accident, he ends up launching costly frontal assaults at Malvern Hill.
The Second Manassas Campaign is in many ways Lee's crowning achievement strategically. Faced with the dual threat of McClellan still on the James and John Pope's advance in Northern Virginia, Lee carefully manages his forces, detaching enough troops to blunt Pope's advance. When McClellan shows signs of withdrawing, Lee acts immediately and decisively, racing north with most of his army to confront Pope. Pope conducts a competent withdrawal behind and defense of the Rappahannock line, preventing any major clash initially, so Lee takes a risk to seize the initiative again, detaching Jackson to strike into the rear of Pope's army at his supply lines, and causing Pope to lose control of the campaign. Lee and Longstreet follow, and at the Battle of Second Manassas, a battle fought on as even terms as Lee ever gets, he decisively defeats Pope and brings the Union war effort in the east to its nadir.
Overall I think Lee was a superb operationalist and his campaign ideas were certainly good.
However, Lee's primary flaw was his insistence to give battle whenever the opportunity presented itself, and his strategic idea to win the war was rather flawed. Lee's strategy was consistent: defend Virginia against Union advances, then take the war north to keep the enemy off balance, subsist off their land, and try to win victories to damage Northern morale and destroy their armies. This is where Lee's flaws start to show: Lee had the opportunity to escape Sharpsburg a few days before the battle began, but instead of withdrawing he ordered the Army of Northern Virginia to concentrate at his position, and in fact, thought of attacking McClellan's right flank. The result was 10,000 casualties that the Confederates could not replace. In addition, once Lee's strategy of annihilation starts breaking down from the casualties suffered, Lee still pursued this strategy for some time after it had ceased to hold any true promise for the Confederacy.
Looking at the whole war the Union had far more generals who were successful in roles of independent and higher command than the Confederates.
I suppose I'll post the rest of my thoughts later, writing this down burned me out a bit.