The U.S. Supreme Court case Pittsburg and Southern Coal Company v. Louisiana in 1894 revolved around a dispute over taxation of interstate commerce. The state of Louisiana imposed taxes on the coal company for its operations within the state, which included both intrastate and interstate activities. The coal company argued that this tax was unconstitutional as it violated the Commerce Clause by taxing interstate commerce, an area under federal jurisdiction. However, the Supreme Court ruled in favor of Louisiana stating that while states cannot interfere with or tax interstate commerce directly, they can impose taxes on businesses operating within their borders even if those businesses also engage in interstate trade. This decision upheld states' rights to levy taxes on corporations doing business within their boundaries without violating constitutional protections against interference with interstate commerce.

In the dissenting opinion for Pittsburg and Southern Coal Company v. Louisiana, it was argued that the tax imposed by Louisiana on coal mined in other states but sold within its borders violated the Commerce Clause of the U.S. Constitution. The dissenting justices believed that this tax unfairly discriminated against interstate commerce because it placed a heavier burden on out-of-state companies compared to those operating solely within Louisiana's borders. They contended that such protectionist measures were not only unconstitutional but also detrimental to free trade among states, which is one of the fundamental principles underpinning our federal system of government. Furthermore, they disagreed with majority’s interpretation of previous case law and insisted that these precedents did not support upholding such discriminatory taxation practices.