Newman v. Arthur, Collector was a United States Supreme Court case that dealt with the issue of whether a tax imposed on the sale of certain goods was unconstitutional. The case was brought by a merchant, Newman, who had been assessed a tax on the sale of certain goods. Newman argued that the tax was unconstitutional because it was a direct tax, which was prohibited by the Constitution. The Supreme Court held that the tax was not a direct tax, and thus was constitutional. The Court reasoned that the tax was not a direct tax because it was imposed on the sale of goods, rather than on the property itself. The Court also held that the tax was not a violation of the Constitution because it was imposed on the sale of goods, rather than on the property itself. The Court concluded that the tax was constitutional and that Newman was liable for the tax.

In Newman v. Arthur, Collector, the Supreme Court was tasked with determining whether a tax imposed on certain imported goods violated the Fifth Amendment of the United States Constitution. The majority opinion held that it did not violate any constitutional rights and thus upheld the tax. However, Justice Field dissented from this decision and argued that Congress had exceeded its authority in imposing such a tax as it was an unconstitutional burden upon interstate commerce. He further argued that while Congress has broad powers to regulate foreign trade, they do not have unlimited power to impose taxes or duties on imports which would interfere with free trade between states or countries. Thus he concluded that this particular law should be struck down as unconstitutional because it interfered with interstate commerce without due process of law and therefore violated both Article I Section 8 Clause 3 of the Constitution as well as the Fifth Amendment's Due Process clause.