“ The inconvenience consequent upon the running of a railroad through a city, under state authority, is not a nuisance in law, but is insuperably connected with the exercise of the franchise granted by the state. If the police power could lay hold of such inconveniences, and make them the basis of the right to repeal such an ordinance, the contract could be abrogated because of the very growth in population and business the railroad was intended to secure.
The power to regulate implies the existence, and not the destruction, of the thing to be controlled. ”

“ The ordinance passed in pursuance of the Indiana statute was an entirety. When accepted it became binding in its entirety. If the city has the right to repeal the specific provisions of the contract, it has the like right to repeal the more general grant to lay a single track. If South Bend can do so, every other municipality having granted like rights, under similar ordinances, and affecting every line of railway in the country, can repeal the franchise to use double or single track. ”

“ On the ground of congestion of traffic, the state's grant and command to operate a continuous road could be nullified by municipal action, to the destruction of great highways of commerce, similar in their nature to the street itself. Such consequences, though improbable, are rendered impossible by the provision of the Constitution of the United States prohibiting the impairment of the obligation of a contract by legislation of a state, whether acting through a general assembly or a municipality exercising delegated legislative power. ”