The U.S. Supreme Court case Louisiana v. Texas in 1899 revolved around a dispute between the two states over quarantine regulations that Texas had imposed to prevent the spread of yellow fever from New Orleans, Louisiana into Texas. The state of Louisiana argued that these restrictions were unconstitutional as they interfered with interstate commerce and violated federal authority over such matters. However, the Supreme Court ruled in favor of Texas, stating that it was within its rights to protect itself against potential health threats by imposing reasonable quarantine measures on incoming traffic from affected areas like New Orleans. The court held that while Congress has power over interstate commerce, this does not deprive states their police powers for protection of public health unless there is an explicit conflict with federal law or constitution.

In the dissenting opinion for Louisiana v. Texas, Justice Harlan argued that the state of Louisiana had a legitimate claim against Texas because its quarantine laws were negatively affecting interstate commerce. He believed that these laws were not justifiable as public health measures and instead served to protect local industries from competition. Furthermore, he maintained that it was within the Supreme Court's jurisdiction to intervene in this matter since it involved a conflict between states which could not be resolved through ordinary legal channels or by Congress. Therefore, he disagreed with the majority's decision to dismiss Louisiana's complaint without hearing any evidence on its merits.