In the case of Williams, Treasurer v. Eggleston in 1897, the US Supreme Court ruled on a dispute involving taxation and property rights. The plaintiff was John R. Williams, who served as treasurer for Wayne County in Michigan while the defendant was Charles A. Eggleston, an individual taxpayer from Detroit city within that county. The issue at hand involved tax assessments levied against certain properties owned by Eggleston which he claimed were unjustly high due to being based on inflated valuations of his real estate holdings. Eggleston argued that these overvaluations violated his constitutional right to equal protection under law because they resulted in him paying more taxes than other property owners with similar assets but lower assessed values. However, the court disagreed with this argument and upheld the validity of such differential tax assessments provided they were not arbitrary or discriminatory but rather reflected genuine differences in market value among different properties. The justices reasoned that it is permissible for local governments to use their discretion when assessing property values for taxation purposes so long as their methods are reasonable and fair overall even if some individual taxpayers might end up paying more than others due to variations in how much their specific properties are worth according to those assessments.

In the dissenting opinion for Williams v. Eggleston, Justice Harlan argued that the majority's decision was inconsistent with previous rulings of the court and violated principles of equity. He contended that a state could not retroactively alter its tax laws to disadvantage certain taxpayers without violating their constitutional rights. In this case, Illinois had changed its law to prevent taxpayers from using certain deductions they were previously entitled to use in calculating their tax liability. Harlan believed this change unfairly targeted those who had relied on these deductions in making financial decisions and investments, thereby infringing upon their property rights without due process of law. Furthermore, he asserted that such retroactive changes created uncertainty and instability in business affairs which contradicted public policy objectives.