The discovery of gold in California and the immense territorial gains by the Treaty of Guadalupe Hidalgo magnified America’s interest in securing a quick commercial route westward. A trans-isthmian canal or railroad was a promising option, but the British had seized/occupied/established protectorates over much of the Central American territory assumed to be the ideal location for such a venture. President Monroe had declared in December 1823 that “the American continents . . . are henceforth not to be considered as subjects for future colonization by any European power,” but Britain’s actual presence in the Bay Islands, the Mosquito Coast, and parts of present-day Honduras had to be taken into account.

Secretary of State John M. Clayton and Henry Lytton Bulwer, the British Minister Plenipotentiary to Washington, produced a agreement that became known as the Clayton-Bulwer Treaty after both parties ratified it. Clayton-Bulwer established the principle that neither nation would have exclusive control over any future canal; both would protect the canal and guarantee its neutrality, and neither would “occupy, or fortify, or colonize, or assume or exercise any dominion over . . . any part of Central America.” The treaty was immensely unpopular in America, as it seemed to reward Britain for its outright defiance of the Monroe Doctrine. The restriction on independent American initiative was lifted a half-century later with the Anglo-American Hay-Pauncefote Treaty (1901).

Now for the pictures:

President Zachary Taylor’s message urging the Senate to ratify “an arrangement so well calculated to diffuse the blessings of peace, commerce, and civilization”:

The Senate resolution proposing that the Senate advise and consent to the ratification of the agreement between Clayton and Bulwer:

The treaty was ratified by a vote of 42-11. Here’s the sheet on which the roll-call vote was taken:

A piece of correspondence from Secretary Clayton to Bulwer:

Lastly, my own Bulwer autograph: