Ashburner v. California was a United States Supreme Court case that dealt with the issue of whether a state could tax a non-resident's income from a business located in the state. The case was brought by a non-resident of California, who owned a business in the state. The state of California had imposed a tax on the non-resident's income from the business, and the non-resident challenged the tax as unconstitutional. The Supreme Court held that the tax was constitutional, and that the state of California had the right to impose a tax on the non-resident's income from the business. The Court reasoned that the state had a legitimate interest in taxing the income of non-residents who were conducting business within the state, and that the tax was not an unconstitutional burden on interstate commerce. The Court also noted that the tax was not discriminatory, as it applied equally to all non-residents conducting business in the state. In conclusion, the Supreme Court held that the state of California had the right to impose a tax on the non-resident's income from the business, and that the tax was not an unconstitutional burden on interstate commerce. The Court's decision established that states have the right to tax the income of non-residents who are conducting business within the state.

In Ashburner v. California, the United States Supreme Court was tasked with determining whether a state court had jurisdiction to hear an appeal from a federal district court decision. The majority opinion held that the state court did not have such authority and thus could not hear the case. Justice Field dissented, arguing that under Article III of the Constitution, Congress has power to grant appellate jurisdiction to any tribunal it deems fit and in this instance had done so by granting concurrent appellate jurisdiction over certain cases between federal courts and state courts. He further argued that since Congress had granted such authority in this instance, then it should be respected as valid law regardless of what other provisions may exist within either body's respective laws or constitutions.