[1] He was the recipient of the Order of the Holy Sepulchre, a papal knighthood conferred by Pope John Paul II.

In 1949, in a deal involving homestead development of the area of Waimea in Hawaii County, as a lawyer with Parker Ranch attorney Garner Anthony, Quinn brokered a deal with the Territorial Land Office and Hawaiian Homes Commission to allow the ranch a more lengthy period of time in which to evacuate the property.

Quinn worked closely with Congressional Delegate John A. Burns on the Hawaii Statehood Commission.

He was president of Dole Pineapple Company from 1965 to 1972, and chairman of the board of both the Honolulu Symphony and the East-West Center.

[10] Quinn lectured, occasionally traveled on the public speaking circuit serving as a Republican elder statesman, and spent time with his family in Hawai'i.