A British Panama Canal after the Darien scheme

How would a British-controlled Panama and canal affect the post-Civil War United States Navy?

It would make close Anglo-American relations strategically important, while Britain would build the canal only if American traffic made tolls and control profitable.

British routes and supporting infrastructure already ran east through Suez, reducing the strategic case for a Panama canal. Canada's principal trade facilities faced Britain, and its transcontinental railway offered another way to cross the country. American Atlantic-Pacific traffic would provide the stronger reason for building the canal. British financiers might invest if that traffic promised returns, without Britain itself necessarily undertaking the project. Toll income and the power to close the passage would then give the United States a reason to maintain good relations with the canal's controller. The earlier Darien premise remains disputed, particularly whether adequate naval supply could have kept the colony alive.