His parents taught at the Hilo Mission boarding school founded by David Belden Lyman and his wife.

In 1846, the family moved to teach at a similar school at the Waiʻoli Mission near Hanalei, Hawaii, on the northern coast of the island of Kauaʻi.

[2] He graduated from Punahou School 1850–1860,[3] and worked for Samuel Gardner Wilder loading a shipload of guano from Jarvis Island.

Using his engineering training, he designed an irrigation system to bring water from the wet mountains to the sugarcane fields, an idea later copied by many other planters.

[10] Younger brother Albert Spencer Wilcox was born May 24, 1844, married Luahiwa, and then Emma Mahelona, became a wealthy plantation owner and politician, and died July 7, 1919.

[11] Another younger brother Samuel Whitney Wilcox was born September 19, 1847, at Waiʻoli, married Emma Lyman (daughter of the Hilo missionaries), had six children, and died May 23, 1929.