He was the son of a man named Ehu, a recipient of the Great Māhele who owned land in the Mānoa Valley. Maikai became part of the early generations of Hawaiian youths educated at the Lahainaluna Seminary on the island of Maui by the American Protestant missionary Lorrin Andrews. He graduated in 1845 with high honors. He initially went into governmental service as a secretary of Mataio Kekūanāoʻa, the Governor of Oahu. He later became a lawyer and was appointed a district justice, although he continued his law practice and working as a member of the Hawaiian bar. American diplomat David L. Gregg, who witnessed one of his cases, noted, "I thought he displayed extraordinary accuteness in the management of the case. His speech to the jury was graceful and apparently eloquent." He was elected a member of the House of Representatives, the lower house of the legislature of the Kingdom of Hawaii, and sat in the legislative assembly sessions of 1848, 1850, 1853, 1854, 1855, and 1856. His contemporaries noted, "Maikai was one of the most eloquent and able members of the House of Representatives, and his liberal policy and tact in debate gave him an influence to which few of his compeers attained." He became an aide-de-camp on the military staff to King Kamehameha III. He was enlisted by Lieutenant Commander Prince Alexander Liholiho, who would later succeed to the throne as King Kamehameha IV, to help re-organize the Hawaiian Army. He initially held the rank of Brevet Captain of Infantry. On August 25, 1854, Prince Alexander Liholiho appointed him as Akukana Kenela, or Adjutant General to the Forces of the Hawaiian Islands to succeed the previous office holder Major Francis Funk. He was placed in charge of all military accounts for the kingdom and held this post until his death. He later achieved the rank of Major. One of his protégés during this period was the futureKing Kalākaua who served as the military secretary to Maikai. On October 3, 1859, he was appointed as a member of the Privy Council of State, the advisory council to King Kamehameha IV. He was also appointed a life member of the House of Nobles, but only participated in the extraordinary session of 1859 in which Prince Albert Edward Kamehameha was conferred as heir-apparent to the throne. He did not get a chance to sit in the legislative session of 1860. Maikai at his home in Honolulu, on May 27, 1860, at the age of thirty-two. On June 28, 1861, John Owen Dominis was appointed as his successor to the position of Adjutant General.
Marriage and descendants
His wife was the High Chiefess Abigail Kapoʻoloku Maikai, who survived him and lived into the reign of King Kalākaua. Their son Samuel Ikuwa Ulumaheihei Maikai would later serve as a lieutenant in the Royal Household Guard, a sub-lieutenant of the Royal Hawaiian Navy on HHMS Kaimiloa, and a military aide during the reign of King Kalākaua. By his first marriage to Wahineopio, Samuel had three children: David Unualoha Maikai, Samuela Kahilolaamea Maikai, and Abigaila Kalanikuikepooloku Maikai. By his second marriage to Annie Palekaluhi Kaikioʻewa, sister of Edward Kamakau Lilikalani, he had a daughter named Helina Kaiwaokalani.
