Claim: Besides Britain ceding land ownership and control in Central American, the Clayton-Bulwer Treaty also involved the US and UK refraining from taking new land in the region, or building a canal there unless it was accessible to both parties.
Evidence: Binding both nations not to "occupy" any part of Central America or the Mosquito Coast necessitated the abandonment of British colonies and protectorates in Central America, and the United States government demanded the British completely abandon their Central American colonies and protectorates, which Britain demurred in doing so. There were three main provisions in the treaty: neither nation would build such a canal without the consent and cooperation of the other; neither would fortify or found new colonies in the region; when a canal was built, both powers would guarantee that it would be available on a neutral basis for all shipping. Finally, it stipulated that neither signatory would ever "occupy, or fortify, or colonize, or assume or exercise any dominion over Nicaragua, Costa Rica, the Mosquito Coast or any part of Central America", nor make use of any protectorate or alliance, present or future, to such ends. It bound both parties not to "obtain or maintain" any exclusive control of the proposed canal, or unequal advantage in its use. The treaty was signed on April 19, 1850, and was ratified by both governments, but before the exchange of ratifications the British Prime Minister Lord Palmerston, on June 8, directed Bulwer to make a "declaration" that the British government did not understand the treaty "as applying to Her Majesty's settlement at Honduras, or its dependencies." Clayton made a counter-declaration which recited that the United States did not regard the treaty as applying to "the British settlement in Honduras commonly called British-Honduras. .. nor the small islands in the neighborhood of that settlement which may be known as its dependencies"; that the treaty's engagements did apply to all the Central American states, "with their just limits and proper dependencies" (referring to the Mosquito Coast and the Bay Islands); and that these declarations, not being submitted to the United States Senate, would in no way affect the legality of the treaty.