In the 1918 case of Missouri & Arkansas Lumber & Mining Company v. Greenwood District of Sebastian County, Arkansas, et al., the U.S. Supreme Court dealt with a dispute over property taxes. The lumber company had purchased land in Sebastian County and paid all due taxes at that time but later discovered there were unpaid back-taxes from previous years which they were being held responsible for by local authorities. The company argued this was unfair as they had no knowledge of these debts when purchasing the land and believed it should be exempted from paying them under Article IV, Section 2 of the Constitution (the Privileges and Immunities Clause). However, the court ruled against them stating that while this clause does protect out-of-state citizens from discrimination by another state's laws, it doesn't guarantee exemption from obligations such as tax liabilities attached to properties within those states regardless if they knew about them or not before purchase.

In the dissenting opinion for Missouri & Arkansas Lumber & Mining Company v. Greenwood District of Sebastian County, Arkansas, it was argued that the majority's decision to uphold a tax assessment on timberland owned by the lumber company in Arkansas violated principles of equal protection under law. The dissenting justices contended that there was clear evidence showing an unequal and discriminatory application of tax laws against non-resident corporations like the plaintiff. They maintained that while resident landowners were assessed at only a fraction of their property’s actual value, non-residents were taxed based on full market value. This discrepancy constituted unfair treatment and discrimination against out-of-state businesses contrary to constitutional guarantees for equal protection under law as per Fourteenth Amendment rights. Therefore, they disagreed with upholding such taxation practices.