In this Supreme Court case, both of these companies had charters to make bridges to connect Cambridge and Boston in Massachusetts. Since the Charles River Bridge Company received the first charter, it was argued that the state of Massachusetts was in the wrong for approving Warren Bridge to also make a nearby bridge with the same purpose, as the company worried it would affect profits from tolls. In the end, Warren Bridge won the case, and both companies made their bridges.
This case had been re-argued after the court initially agreed there was a breach in contract with Massachusetts approving the Warren Bridge. The decision was that there were no exclusive rights just because Charles River Bridge Company got the charter first and that allowing the Warren Bridge would be good for the community.