Southwestern Railroad Company v. State of Georgia was a case heard by the United States Supreme Court in 1875. The case involved a dispute between the Southwestern Railroad Company and the State of Georgia over the taxation of the company's property. The company argued that the taxation of its property was unconstitutional, as it violated the Fourteenth Amendment's Equal Protection Clause. The Court held that the taxation of the company's property was not unconstitutional, as the state had a legitimate interest in taxing the company's property. The Court also held that the taxation of the company's property did not violate the Fourteenth Amendment's Equal Protection Clause, as the taxation was based on a reasonable classification of property. The Court also held that the taxation of the company's property did not violate the Due Process Clause of the Fourteenth Amendment, as the taxation was not arbitrary or capricious. The Court thus affirmed the decision of the lower court, which had upheld the taxation of the company's property.

In Southwestern Railroad Company v. State of Georgia, the Supreme Court was asked to decide whether a state could tax railroad property located within its borders. The majority opinion held that it could not, as such taxation would be an unconstitutional burden on interstate commerce and thus violate the Commerce Clause of the Constitution. Justice Field dissented from this decision, arguing that states should have authority to impose taxes on railroad companies operating within their boundaries in order to raise revenue for public purposes or services provided by those states. He argued that while Congress has exclusive power over interstate commerce, it does not have exclusive power over intrastate activities like taxation; rather, he believed these powers were reserved for individual states under the Tenth Amendment. Furthermore, he argued that since railroads are private corporations created by state law and operate solely within one state's jurisdiction they should be subject to reasonable taxation just like any other business entity incorporated in a particular state is subject to local taxes imposed by that same government body.