In addition to being prohibited by the Fourteenth Amendment from depriving any person of life, liberty, or property, without due process of law, the States are, by Section X, Article I of the Constitution, expressly denied the power to pass any law impairing the obligation of contracts. This provision, the general intent of which is sufficiently plain, has, in its application given rise to a multitude of cases requiring adjudication in the courts. The purposes of this treatise will not require us, however, to examine these cases in detail. Elsewhere in this treatise, certain specific applications of the prohibition are considered.1 In this chapter the aim will be, as it was the aim in the chapter dealing with due process of law, to ascertain the broad and underlying principles which have governed the federal courts in the enforcement of the prohibition.

As has been already seen, the due process of law clause of the Fourteenth Amendment protects the individual in his right to enter into contracts not contrary to public policy. The provision under consideration protects from impairment the obligation of the contract when entered into.

So far as this provision is concerned, a state law divesting vested rights is not invalid, unless these rights are founded upon contracts, and the effect of the law is thus to impair or nullify their force.2

1 See especially the discussion of suits against the States, and the enforcement of state law by the federal courts.

2 Satterlee v. Matthewson, 2 Pet. 380; 7 L. ed. 458: B. & S. R. R. v. Nesbit, 10 How. 395; 13 L. ed. 469; Bronson v. Kinzie et al., 1 How. 311; 11 L. ed. 143.