The commissioner responsible for the assessment of and collection of contributions to the Washington state (plaintiff) unemployment fund served a notice of assessment on International Shoe (defendant), a manufacturer and seller of shoes and footwear, for failure to pay into the fund during the years 1937 to 1940. International Shoe was a Delaware corporation with its principal place of business in Missouri. The Commissioner served the notice of assessment upon a salesman employed by International Shoe in Washington State. International Shoe moved to set aside the notice on the grounds that it was not a corporation doing business in Washington, had no registered agent within the state, and was not an employer and did not furnish employment within the state as defined under state law. The unemployment office's appeal tribunal denied International Shoe's motion to set aside the notice and held that the commissioner was entitled to recover the contributions. That decision was affirmed by the commissioner, the county superior, and the Washington Supreme Court. International Shoe appealed to the United States Supreme Court.