Born in 1920 in Miami, Arizona—a small mining town located 85 miles east of Phoenix—Jack was one of two children of Millard Elam (1887–1965) and Alice Amelia, née Kerby (1884–1924)[2][3] Jack's father supported the family by working assorted jobs over the years, including stints as a carpenter, millman, and accountant.

[3][4][a] The Elams by 1924 had moved from Miami to the nearby community of Globe, Arizona, where in September that year Alice died at the age of 40, succumbing to what state medical records cite as a three-year struggle with "general paralysis".

[6][7] Federal census records show that two years later the children, their father, stepmother, and Flossie's own mother were residing together in Globe, where Millard had a new job as an investigator for a loan company.

[8] Flossie was employed as well at the time as a public school teacher, while Jack also contributed to the family's income by periodically working on nearby farms gleaning cotton.

Percy Shain, a veteran film and television critic for The Boston Globe, interviewed Elam in 1974 and quoted the actor's comments about the injury:I lost my eye when I was 11 in a fight at—would you believe it?—a boy scout meeting...It was a big initiation night but I got into a scrap with this other kid and he put a pencil through my eye.There was no doctor there and it wasn't looked at until sometime afterward.

[11] Before becoming an actor, Elam completed his high-school education, got married, attended college, worked in a variety of jobs, and, despite being blind in one eye, served two years in the U.S. Navy during World War II.

[9] He completed his secondary education in Arizona, graduating from Phoenix Union High School in the late 1930s and then moving to California, where he majored in "business studies" at Modesto[12] and Santa Monica junior colleges.

[9][b] During that time, he was also employed in several positions before entering military service, including work as a salesman for a "house trailer agency",[13] as an accountant for the Standard Oil Company, a bookkeeper at the Bank of America, and a manager at the Hotel Bel-Air in Los Angeles.

[6][9][14] For a few years after his discharge from the navy, Elam continued to apply his business training as an accountant for Hopalong Cassidy Productions and as an independent auditor for Samuel Goldwyn and other moguls and companies associated with the film industry.

'"[16] Elam made his screen debut in 1949 in She Shoulda Said No!, an exploitation film in which a chorus girl's habitual marijuana smoking ruins her career and then drives her brother to suicide.

[17] On television in the 1950s and 1960s, he made multiple guest-star appearances on many popular Western series, including The Lone Ranger, Gunsmoke, The Rifleman, Lawman, Bonanza, Cheyenne, Have Gun – Will Travel, Zorro, The Rebel, F Troop, Tales of Wells Fargo, The Texan, and Rawhide.

[20] The next year, for the Harold Hecht production The Way West, he was chosen for another light-hearted role, playing Preacher Weatherby and providing support to costars Robert Mitchum, Richard Widmark, and Kirk Douglas in a story about a wagon train traveling the Oregon Trail.

Elam in one sequence spends a good portion of his screen time simply trying to rid himself of an annoying fly, finally capturing the elusive insect inside the barrel of his pistol.