In 1886, when a Chinese laundry owner challenged the constitutionality of a San Francisco ordinance clearly designed to drive Chinese laundries out of business, the U.S. Supreme Court ruled in his favor, and in doing so, laid the theoretical foundation for modern equal protection constitutional law. See "Yick Wo v. Hopkins", 118 U.S. 356 (1886). Meanwhile, even with severe restrictions on Asian immigration, tensions between unskilled workers and wealthy landowners persisted up to and through the Great Depression. Novelist Jack London writes of the struggles of workers in the city of Oakland in his 1913 novel "The Valley of the Moon".