Born in Stamford Township, Delaware County, New York, he left home in 1850 headed for the gold fields of California with his brother John.

In both appearances and actions he had all the characteristics of a model western lawman: tall, handsome, modest, reticent, quietly efficient, and resourceful in his use of modern detection methods, including the science of ballistics.

Witnesses in settlements near the scenes of the robberies described seeing a polite, friendly man in his fifties, about five foot eight or ten in height with brownish gray hair, a fierce gray mustache and matching goatee, carrying a bedroll (which Hume correctly inferred carried his duster, sack disguise, shotgun and loot), passing through on foot and quickly disappearing.

Hume’s major break occurred on November 3, 1883, when Bart robbed a Wells Fargo coach headed from the town of Sonora to Milton, in Calaveras County.

Hume engaged with special detective Harry Morse, former sheriff of Alameda County, spending a week visiting every laundry in San Francisco – nearly a hundred of them, to track down where the mark originated from.

Hume and Morse were real detectives of the time, outside of the Pinkerton Agency and Wells Fargo Operations, traditional law work consisted primarily of forming posses, serving warrants with a gun, and preventing mobs from lynching the miscreants.

In "Black Bart," the sixteenth episode of the first season of Stories of the Century, the show's protagonist, Railroad Detective Matt Clark (Jim Davis) portrays the role that Hume played in real life.

In "Black Bart," the fourth episode from the third season of Death Valley Days, the battle of wits between Hume, played by John Damler, and a wily stage robber is dramatized.