The courts have generally held that direct taxes are restricted to taxes on people (variously called capitation, poll tax or head tax) and property. (Penn Mutual Indemnity Corp. v. C.I.R., 227 F.2d 16, 19-20 (3rd Cir. 1960).) All taxes are known as "indirect taxes," basically tax an event, rather than somebody or property by itself. (Steward Machine Co. v. Davis, 301 U.S. 548, 581-582 (1937).) What were a straightforward limitation on the power of the legislature based on the topic of the tax pr...