Whenever one nation possesses a commodity coveted by another nation, conflict ensues. Thus it was with guano during the nineteenth century. In his 1852 State of the Union address, Millard Fillmore said:
The correspondence of the late Secretary of State with the Peruvian charge d'affaires relative to the Lobos Islands was communicated to Congress toward the close of the last session. Since that time, on further investigation of the subject, the doubts which had been entertained of the title of Peru to those islands have been removed, and I have deemed it just that the temporary wrong which had been unintentionally done her from want of information should be repaired by an unreserved acknowledgment of her sovereignty.
I have the satisfaction to inform you that the course pursued by Peru has been creditable to the liberality of her Government. Before it was known by her that her title would be acknowledged at Washington, her minister of foreign affairs had authorized our chargé d'affaires at Lima to announce to the American vessels which had gone to the Lobos for guano that the Peruvian Government was willing to freight them on its own account. This intention has been carried into effect by the Peruvian minister here by an arrangement which is believed to be advantageous to the parties in interest.
The "late Secretary of State" was none other than Daniel Webster. On June 2, 1852, a Captain John C. Jewett sent a letter to Webster asking whether American citizens could take guano from the Lobos Islands in the Pacific. Webster replied in a letter dated June 5, 1852, that it was the position of the Department of State that neither Peru nor any other country had legal claim to the Lobos Islands and the guano thereon, and on the same day, Webster sent a letter to the Secretary of the Navy, suggesting the Navy protect anyone obtaining guano from the Lobos. As events unfolded, much hue and cry arose over Webster's first letter to Jewett, authorizing Americans to harvest guano from the Lobos Islands, and whether President Fillmore had approved the letter. A draft of the letter initialled by Fillmore was subsequently found, although he denied any recollection of approving it. The controversy was taken up by the press in the U.S., as well as in Peru, as shown in this excerpt from a letter from the American Chargéd'Affaires in Lima.
Reports of Committees 30th Congress, 1st Session - 48th Congress, 2nd Session By United States Congress. Senate
Extensive correspondence between Peru and the U.S. convinced the U.S. government that Peru in fact owned the Lobos, and Webster reneged on his promise of Naval protection for Jewett, much to the chagrin of Capt. Jewett and his partner Mr. A.G. Bensen, who chartered several vessels to go to the Lobos under the protection implied by Webster's promise to Jewett. When Bensen's ships arrived at Peru, they were not allowed to take guano from the Lobos Islands, but a deal was struck whereby they could load guano at the Cinchas Islands, and Bensen was to be paid 20 dollars a ton by the Peruvians for hauling the guano. The deal did not go smoothly, and Bensen evetually filed claims against the U.S. government and Peru. The claims were considered by the Committee of Claims of the Senate in 1856 and 1857, but I haven't yet been able to find the ultimate outcome.