L.N. Irwin was born on a farm near Galesberg, Illinois. He received his secondary education in Galesberg and later graduated from Knox College with a BA degree, having studied classical subjects. He next spent a year-and-a-half as a YMCA secretary in Hartford, Connecticutt before heading west. He put in two years on a ranch near Laramie, Wyoming, before being called back to Galesberg to take over the operation of his father's dairy farm. L.N., as he was known, married Katherine Williams, who had been a coed at Knox College.

In 1911 the Irwin family of three came to California, arriving in Davis on Christmas day. They purchased forty acres of farm land four miles west of Davis and built a dairy barn, the loft of which served as their temporary home. From this beginning and with careful management and hard work, L.N. built up one of the finest Holstein-Friesian herds in the state. He later acquired an additional forty acres of farm land as well as considerable real estate in Davis.

L.N. Irwin was not only a breeder of good cattle and a successful farmer, he was also a devoted husband and father and is remembered as an outstanding citizen in the Davis community. He donated the Gordon H. True Service Cup, named in honor of Professor True, Chairman of the Animal Husbandry Department at UCD and a founder of the Purple Circle. In 1951 L.N. donated a second permanent trophy, this one named after his friend C.A. Cowell and now presented annually on the Fourth of July to the outstanding citizen of the community.