In International Harvester Co. v. Wisconsin Department of Taxation, 322 U.S. 435 (1944), the state of Wisconsin imposed a tax on income derived from dividends paid to stockholders, including nonresidents, as measured by income earned by the corporation in Wisconsin. The Supreme Court upheld the tax as valid because "a state may tax such part of the income of a non-resident as is fairly attributable either to property located in the state or to events or transactions which, occurring there, are subject to state regulation and which are within the protection of the state and entitled to the numerous other benefits which it confers." Id. at 441-42.