The Samoan Islands are an archipelago that covers just over 3,000 km2 (1,170 sq mi) in the central South Pacific. In the late 19th century, Germany and the United States agreed on the partition of the islands, with the western half coming under German control, with the eastern islands becoming American Samoa, an unincorporated territory of the United States on April 17th 1900. At that time the High Chiefs of Manu’a did not wish to cede their group of islands and opted out of the agreement.
Four years later in 1904, Tui Manu’a Elisara, the King of Manu’a, signed a Deed of Succession swearing allegiance to the United States and ceding the Manu’a Islands as a protectorate of the United States.
Since then, July 16th has been observed as Manu’a Cession Day, although it was not made a public holiday until 1983 when the first official celebration was held in the Manu’a Islands with a church service, parade, and cultural activities.