ANSWER: Yes, but the 1878 Treaty-pact is reaffirming an already strong friendship and other standing treaties between Eastern Samoa and the Union-side of the United States. Trade and Treaty pacts between Eastern Samoa and the Union-side of the USA began in 1839 (almost 40 years earlier) with Commander Wilkes who was on a military survey Expedition. The first Treaty-pact was draftered with 16 articles covering protection for vessels, sailors and shore-leave, military wreckage, along with authoritive powers in the harbor.
In 1868, just 10 years earlier the White House had been infiltrated by a pro-Confederate Vice President Andrew Johnson and after the assassination of Lincoln, Andrew Johnson became President, then became the first US. President to be 'impeached from office'. In 1869, the 18th President General Ulysses S. Grant is elected to not only bring back order but to expand, renew, or reaffirm ties with overseas friends including ancient Eastern Samoa houses, Ireland, and neighboring ones (including Native American Confederations). The US. American NEWS headlines at the time, and other published works can either be 'for-or-against' the new President Grant Administration as there is much internal conflict within the USA from 1860-1890s.
In the clipped article below it says that Eastern Samoa sought 'prototection', doesnt mention at all any previous alliances. Eastern Samoa though was not under threat, at War, or in any danger..however the Union States had just been through its first Civil War in 1861 and Grant's Administration had the task of creating a new USA. During the Civil War the Confederates had overseas European allies and arms supplies and Imperial Britain was contending for favor in Western Samoa against Imperial Germany, even though Western Samoa had already signed a Treaty of Friendship favoring German interests. Following up on US-Samoan relations with Eastern Samoa was politically called for especially when that same year 1900, the Tongan Monarch had signed an alliance with Imperial Britain. Although the 1878 Treaty aggreement might be published about in some books about the USA and Eastern Samoa, talks with the Grant Administration began in 1872 under US. Commander Meade.
A clipped part of an article about the meetings, and like the
NEWS today it is not fully informed on all the proceedings.