Are There Limits To Federal Taxing Power? If So, What Are Those Limits?
Sample Of Federal Taxing Power Cases
But, aside from the obvious error of the proposition, intrinsically considered, it manifestly disregards the fact that by the previous ruling it was settled that the provisions of the 16th Amendment conferred no new power of taxation, but simply prohibited the previous complete and plenary power of income taxation possessed by Congress from the beginning from being taken out of the category of indirect taxation to which it inherently belonged, and being placed [240 U.S. 103, 113] in the category of direct taxation subject to apportionment by a consideration of the sources from which the income was derived,-that is, by testing the tax not by what it was, a tax on income, but by a mistaken theory deduced from the origin or source of the income taxed.
Stanton v. Baltic Mining Co, 240 U.S. 103 (1916)
https://caselaw.findlaw.com/us-supreme-court/240/103.html
We must reject in this case, as we have rejected in cases arising under the Corporation Excise Tax Act of 1909 … and Hays, Collector, v. Gauley Mountain Coal Co. …, the broad content on submitted in behalf of the government that all receipts-everything that comes in-are income within the proper definition of the term 'gross income,' and that the entire proceeds of a conversion of capital assets, in whatever form and under whatever circumstances accomplished, should be treated as gross income.
Southern Pac Co v. Lowe, 247 U.S. 330 (1918)
https://caselaw.findlaw.com/us-supreme-court/247/330.html
The Sixteenth Amendment must be construed in connection with the taxing clauses of the original Constitution and the effect attributed to them before the amendment was adopted. In Pollock v. Farmers' Loan & Trust Co., 158 U.S. 601 , 15 Sup. Ct. 912, under the Act of August 27, 1894 (28 Stat. 509, 553, c. 349, 27), it was held that taxes upon rents and profits of real estate and upon returns from investments of personal property were in effect direct taxes upon the property from which such income arose, imposed by reason of ownership; and that Congress could not impose such taxes without apportioning them among the states according to population, as required by article 1, 2, cl. 3, and section 9, cl. 4, of the original Constitution.
Eisner v. Macomber, 252 U.S. 189 (1920)
https://caselaw.findlaw.com/us-supreme-court/252/189.html