Not only did the United States allow itself a closer intimacy with this new Pacific power than it would have done with a state of Europe, but it exhibited a greater freedom in dealing with the European powers themselves in the Far East than at home or in America. In 1863 the United States joined--in fact, in the absence of a naval force it strained a point by chartering a vessel for the purpose--with a concert of powers to force the opening of the Shimonoseki Straits; subsequently acting with Great Britain, France, and the Netherlands, the United States secured an indemnity to pay the cost of the expedition; and in 1866 it united with the same powers to secure a convention by which Japan bound herself to establish certain tariff regulations. Nor were the relations of the United States with the Pacific Ocean and its shores confined to trade and international obligations. The American flag waved over more than ships and a portion of the Pacific coast. Naval officers more than once raised it over islands which they christened, and Congress authorized the President to exercise temporary authority over islands from which American citizens were removing guano and to prevent foreign encroachment while they were so engaged. In the eighties, fifty such islands of the Pacific were in the possession of the United States. In 1872 an American naval officer made an agreement with the local chieftain of Tutuila, one of the Samoan Islands, for the use of Pago Pago, which was the best harbor in that part of the ocean. The United States drifted into more intimate relationship with the natives until in 1878 it made a treaty with the Samoan king allowing Americans to use Pago Pago as a coaling station. In return the United States agreed: "If unhappily, any differences should have arisen, or shall hereafter arise, between the Samoan government and any other government in amity with the United States, the government of the latter will employ its good offices for the purpose of adjusting those differences upon a satisfactory and solid foundation." In 1884 the Senate insisted on securing a similar harbor concession from Hawaii, and within the next few years the American Navy began to arise again from its ashes. The obligation incurred in exchange for this concession, however, although it resembled that in the Japanese treaty, was probably an unreflecting act of good nature for, if it meant anything, it was an entangling engagement such as the vast majority of Americans were still determined to avoid.