Riggs v. Johnson County was a United States Supreme Court case that was decided in 1867. The case involved a dispute between a landowner, Riggs, and Johnson County, Iowa. Riggs had purchased a tract of land from the United States government in 1856, and the deed to the land included a clause that stated that the land could not be taxed by the county. However, Johnson County had imposed a tax on the land in 1864, and Riggs sued the county to recover the taxes he had paid. The Supreme Court held that the deed to the land was valid and that the county had no authority to impose a tax on the land. The Court reasoned that the deed was a contract between the United States government and Riggs, and that the county had no authority to interfere with the contract. The Court also held that the county had no authority to impose a tax on the land because the deed specifically stated that the land could not be taxed. The Court's decision in Riggs v. Johnson County established the principle that a deed from the United States government is a contract between the government and the purchaser, and that the county has no authority to interfere with the contract. The decision also established that a county cannot impose a tax on land that is specifically exempted from taxation in the deed.

In Riggs v. Johnson County, the Supreme Court was asked to decide whether a county could be held liable for damages caused by its failure to maintain a bridge in good repair. The majority opinion found that counties were not responsible for such damages and thus denied the plaintiff's claim. However, Justice Field dissented from this decision and argued that counties should be held accountable when they fail to properly maintain public roads or bridges. He reasoned that since these are essential services provided by government entities, it is only fair that those who suffer losses due to their negligence should have recourse through legal action against the county itself rather than having no remedy at all. Furthermore, he noted that if governments can escape liability simply because of their status as governmental bodies then there would be little incentive for them to take proper care of public works projects which would ultimately lead to an overall decline in safety standards across the country.