In District of Columbia v. Washington Market Company, the Supreme Court of the United States was asked to decide whether the District of Columbia had the authority to impose a tax on the Washington Market Company. The Washington Market Company argued that the tax was unconstitutional because it violated the Due Process Clause of the Fifth Amendment. The Supreme Court held that the tax was constitutional. The Court reasoned that the District of Columbia had the authority to impose the tax because it was a valid exercise of the District's police power. The Court also held that the tax did not violate the Due Process Clause because it was not arbitrary or oppressive. The Court concluded that the tax was a valid exercise of the District's police power and did not violate the Due Process Clause. The Court therefore affirmed the decision of the lower court and upheld the tax.

In the case of District of Columbia v. Washington Market Company, the Supreme Court was asked to decide whether a tax imposed by Congress on certain businesses in the District of Columbia was constitutional. The majority opinion held that it was not, as it violated Article I Section 8 Clause 17 which gives exclusive power to Congress over taxation within the district. Justice Field dissented from this ruling and argued that while he agreed with much of what had been said in support of striking down the tax, he believed that there were other considerations at play here which should be taken into account when determining its constitutionality. He noted that if Congress has authority under Article I Section 8 Clause 17 to impose taxes for public purposes within D.C., then they also have authority to determine how those taxes are collected and enforced - including through private companies like Washington Market Company who were being taxed here - so long as such regulations do not conflict with any other provision or clause found elsewhere in the Constitution or laws passed by Congress itself.