Despite the myth, Union arms were almost universally crowned with success, especially in the west. The advance in the west went from Forts Henry and Donelson, through Vicksburg and Corinth to Stone's River and Murfreesbourough, down to Atlanta, Savannah and Charleston, with only the single check at Chickamaugua.
"A new England private said that each evening the men in the company would speculate about the number of deserters who would come in that night: "The boys talk about the Johnnies as at home we talk about suckers and eels. The boys will look around in the evening and guess that there will be a good run of Johnnies." Heavy firing on the picket line was always taken to mean that the enemy wsa trying to keep deserters from getting away."
"A Stillness at Apotmattox" pp 330-31, by Bruce Catton
This was interesting:
"It developed that [Alexander]Stephens's [vice president of the so-called CSA] nephew, a Confederate officer, had for twenty months been a prisoner of war on Johnson's Island, in Sandusty Bay. Lincoln made a note of it, and a few days later that surprised young officer found himself called out of prison and seat down to Washington, where be was taken to the White House for a chai with President Lincoln; after which be was sent tbrough the lines to Richmond. The Confederates returned the favor, picking at random a Union officer of the same rank, and so the 13th New Hampshire presently welcomed the return of its Lieutenant Murray, who who was delighted and surprised by the whole business."
Ibid. p 333
Walt
Yet in the eastern theater of the war, the indisputably more prominent of the two, the yankees were hit, against the odds, with defeat after defeat. Manassas 1 and 2, Fredericksburg, Chancellorsville.
You also neglect entirely the far western theater, which was dominated by humiliating yankee defeats by smaller confederate numbers. The Red River and Sabine campaigns ended in disaster for the federals with stunning against the odds defeats at Mansfield and Sabine Pass. The Texas coastal campaign was similarly laughable with the main port at Galveston being retaken by the confederates in a stunning defeat of the yankees, again against the odds. After that and Sabine's failures, the yankees attempted to fight their way up the coast from the Rio Grande. They took Brownsville and used it to work their way north on the coast, just in time for the confederates to come back in behind them and kick them out of Brownsville. The laughable inability of the yankees to effectively do much of anything in the far west theater essentially resulted in the preservation of Texas as the confederacy's main viable cotton and trade source until well after Lee's surrender and the war's end everywhere else in the nation.
But that is not to say they didn't try. Lincoln was ready to devote numbers comparable to all but the large armies in the eastern theater toward the goal of capturing the far west. The invasion stopped at Sabine Pass was intended to consist of between 15 and 20 thousand men with the first 5 thousand of them having been beaten by 44 confederates in an earthen fort. The Red River Campaign was slated to consist of 17,000 under Banks plus another 10,000 sent by Sherman plus another 15,000 under Steele plus a fleet of ironclads and gunboat steamers under Porter. Had the Rio Grande effort gotten anywhere, most expected it would recieve the attention of another 15,000 federals.
Every one of these was by all reasonable considerations a sizable force, and all met with defeat coming nowhere near their objectives. This, combined with the fact that the campaigns couldn't establish themselves inland beyond river entry, we never hear about them.
The eastern theater provided a strong and lengthy confederate check on federal invasion to the point of exhaustion, when they were finally overrun. The western theater was a union push through to the end waged under the practice of total warfare including against civilians. Those are the two we often hear about. The story that is seldom told occured in the far western theater, and it was a complete disaster for the federals time and time again.