"Ua Mau ke Ea o ka Aina i ka Pono" has been translated as: "The Life of the Land is Perpetuated in Righteousness."
The motto was adopted by the Kingdom of Hawai'i in 1843. The saying is attributed to King Kamehameha III as of July 31, 1843, when the Hawaiian flag once more was raised after a brief period of unauthorized ursurpation of authority by a British admiral.
On May 1, 1959, Ua mau ke ea o ka aina i ka pono was adopted as the official motto of the State of Hawaii by Joint Resolution No. 4 of the 30th Territorial Legislature.
The words were used in an address by Kamehameha III at ceremonies following the return of his kingdom from the British. An English sea captain (Paulet) had, in effect, ceded Hawai'i to England, claiming large debts owed by the Hawaiian nobility. He was acting a bit beyond his authority, and Admiral Richard Thomas was dispatched to return sovereignty of the islands to the King. Thomas Square in Honolulu is named for the Admiral.
Before becoming the state of Hawaii's official motto, these words were part of the coat of arms of the Kingdom of Hawaii and the seals of the Republic of Hawaii and the Territory. King Kamehameha III issued this motto upon the restoration of the Hawaiian flag to the kingdom by the British in 1843.
The law designating the official Hawaii state motto is found in the Constitution of the State of Hawaii, Article 15, Section 5.
Article XV State Boundaries; Capital; Flag;
Section 5. The motto of the State shall be, "Ua mau ke ea o ka aina i ka pono." [Add Const Con 1978 and election Nov 7, 1978]
The law designating the official Hawaii state motto is found in the Hawai`i Revised Statutes, Volume 1, Chapter 5, Section 5-9
CHAPTER 5. EMBLEMS AND SYMBOLS.
§5-9 State motto. The motto "Ua mau ke ea o ka aina i ka pono," is adopted, established, and designated as the official motto of the State. It is translated into English to mean "The life of the land is perpetuated in righteousness." [L 1959, JR 4, §1; Supp, §14-5.3; HRS §5-9; am L 1979, c 145, §2]