I am not sure if there were any direct taxes. The Constitution allowed a direct tax based on population, via a census (Article I.2.3, I.9.4;) but I have no source that implies they were collected on a continuous basis. The chief revenue tool was the tariff. It appears the South also considered the increase in the cost of goods sold, such as "carrying trade," to be a tax:
"By mere supineness, the people of the South have permitted the Yankees to monopolize the carrying trade, with its immense profits. We have yielded to them the manufacturing business, in all its departments, without an effort, until recently, to become manufacturers ourselves. We have acquiesced in the claims of the North to do all the importing, and most of the exporting business, for the whole Union. Thus, the North has been aggrandised, in a most astonishing degree, at the expense of the South. It is no wonder that their villages have grown into magnificent cities. It is not strange that they have 'merchant princes, ' dwelling in gorgeous palaces and reveling in luxuries transcending the luxurious appliances of the East! How could it be otherwise? New York city, like a mighty queen of commerce, sits proudly upon her island throne, sparkling in jewels and waving an undisputed commercial scepter over the South. By means of her railways and navigable streams, she sends out her long arms to the extreme South; and, with an avidity rarely equaled, grasps our gains and transfers them to herself—taxing us at every step—and depleting us as extensively as possible without actually destroying us. Meantime, the South remains passive—in a state of torpidity—making cotton bales for the North to manufacture, and constantly exerting ourselves to increase the production as much as possible. We have no ships in the foreign carrying trade, or very few indeed… Lastly, let us at once begin the business of direct importation and direct exportation, and thus keep at home the millions of dollars which we annually pay to the North. The business of direct importation and direct exportation would, of course, build up, as if by the wand of a magician, splendid Southern cities of commercial grandeur and opulence; and thus we might become the most happy, prosperous, wealthy and intelligent people upon whom the sun has ever smiled. All this we should do—not in spitefulness— not in a spirit of envy—not with a view of breaking the ties of national Union—not with a design of engendering sectional animosity, but in obedience merely to the dictates of enlightened sectional policy, and in obedience to that universal principle, so well understood and acted upon by our Yankee friends, of consulting our own pecuniary interests, and adding to our general and individual pecuniary emoluments."
[Vicksburg Daily Whig, January 18, 1860, in Dwight Lowell Dummond, "Southern Editorials on Secession." The Century Co., 1931, pp. 13-14, 15]
This one also alludes to a federally-promoted Northern monopoly on "carrying trade" (transportation of goods,) but also mentions bounties and other factors:
"[W]e think it can be easily shown, though not within the narrow limits of a newspaper article, that the whole policy of the Federal Government, from the beginning has been to build up and enrich the North at Southern expense. In this business that monster engine, a high Protective Tariff, has been the chief instrument. It has enabled the North to do nearly all the importing and exporting business of the country, with immense profit. Besides the Tariff, we have fishing bounties, and navigation laws, and the giving away the public lands, millions of acres at a time, all of which tend to aggrandize the Northern section of the Union."
[New Orleans Daily Crescent, June 15, 1860, in Dwight Lowell Dummond, "Southern Editorials on Secession." The Century Co., 1931, p.127]
This Northern editorial focused exclusively on the protective tariff:
"The South has furnished near three-fourths of the entire exports of the country. Last year she furnished seventy-two percent of the whole… we have a tariff that protects our manufacturers from thirty to fifty percent, and enables us to consume large quantities of Southern cotton, and to compete in our whole home market with the skilled labor of Europe. This operates to compel the South to pay an indirect bounty to our skilled labor, of millions annually."
[Daily Chicago Times, December 10, 1860, in Howard Ceil Perkins, "Northern Editorials on Secession." American Historical Association, 1942, P.573]
This one from early 1861 implies a blockade of Southern ports was in order to protect Northern revenue, mentioning changes in both interstate trade, as well as the tariff:
"One of the most important benefits which the Federal Government has conferred upon the nation is unrestricted trade between many prosperous States with divers productions and industrial pursuits. But now, since the Montgomery [Confederate] Congress has passed a new tariff, and duties are exacted upon Northern goods sent to ports in the Cotton States, the traffic between the two sections will be materially decreased.... Another, and a more serious difficulty arises out of our foreign commerce, and the different rates of duty established by the two tariffs which will soon be in force..."
"The General Government,... to prevent the serious diminution of its revenues, will be compelled to blockade the Southern ports... and prevent the importation of foreign goods into them, or to put another expensive guard upon the frontiers to prevent smuggling into the Union States. Even if the independence of the seceding Commonwealths should be recognized, and two distinct nations thus established, we should still experience all the vexations, and be subjected to all the expenses and annoyances which the people of Europe have long suffered, on account of their numerous Governments, and many inland lines of custom-houses. Thus, trade of all kinds, which has already been seriously crippled would be permanently embarrassed..."
"It is easy for men to deride and underestimate the value of the Union, but its destruction would speedily be followed by fearful proofs of its importance to the whole American people."
[Philadelphia Press, March 18, 1861, in Stampp, Kenneth M., "The Causes of the Civil War." 1986, p.69]
That is only a small fraction of the narrative from those days; but, in general, it was understood that the tariff and "tax" burden was one-sided, in favor of the North.
Mr. Kalamata
So what you are saying is that there was no legally mandated direct tax against Southern states.