The Massachusetts legislature granted Harvard College a license to operate a for-profit ferry on the Charles River in 1650. In 1785, the legislature incorporated P to replace the ferry with a bridge. P got a 40-year charter to receive tolls. The bridge would become state property in 40 years. P began operations in 1786. In 1792, the legislature extended the charter by an additional 32 years. In 1828, the legislature wised up and incorporated D to build another bridge over the Charles River. P and now D’s bridge were to be a few hundred yards apart. The biggest difference was that D’s bridge would become state property in 6 years. P sought an injunction in that the new contract unconstitutionally impaired P's present contract. The Massachusetts Supreme Judicial Court dismissed the bill. The Supreme Court granted certiorari. D's bridge now belongs to the state and operates toll-free. Ps insist that by virtue of the grant of 1650, Harvard college was entitled, in perpetuity, to the right of keeping a ferry between Charlestown and Boston; that this right was exclusive; and that the legislature had not the power to establish another ferry on the same line of travel, because it would infringe the rights of the college; and that these rights, upon the erection of the bridge in the place of the ferry, under the charter of 1785, were transferred to, and became vested in P;'= and that under, and by virtue of this transfer of the ferry right, the rights of the bridge company were as exclusive in that line of travel, as the rights of the ferry. P also contends that the acts of the legislature necessarily implied that the legislature would not authorize another bridge, and especially a free one, by the side of this, and placed in the same line of travel, whereby the franchise granted to the 'proprietors of the Charles River Bridge' should be rendered of no value.