Born in Peoria, Illinois, Donlin's family soon moved to Erie, Pennsylvania, where he lost both his father, railroad conductor John Donlin, and mother, Maggie, in a train accident when he was a young boy.
He was forced to hustle to survive from a young age, worked as a machinist in his youth and was resultantly sickly child.
At 15 years old he found work selling candy on California-bound train.
Once in California, he put down roots.

Donlin was a flamboyant playboy, a sharp dresser and a notorious drinker.
With his dashing looks and one who was not opposed to finding trouble, he was equally popular with women and men and was one of the most popular players in baseball for a short time at the peak of his career.
As a young minor leaguer in California, Donlin asked a San Francisco Examiner employee to run a photograph of him in the paper, saying "I know I'll get a break.
I know I'm going to be great."
A month after Admiral George Dewey's victory at the Battle of Manila Bay, University of Oregon baseball coach Tom Kelly recalled Donlin using a bat that he had painted red, white and blue and named "Dewey."

In October 1914 Donlin married actress Rita Ross, known for her part in the musical comedy team, Ross & Fenton.
Born in Peoria, Illinois, Donlin's family soon moved to Erie, Pennsylvania, where he lost both his father, railroad conductor John Donlin, and mother, Maggie, in a train accident when he was a young boy. He was forced to hustle to survive from a young age, worked as a machinist in his youth and was resultantly sickly child. At 15 years old he found work selling candy on California-bound train. Once in California, he put down roots.
Donlin was a flamboyant playboy, a sharp dresser and a notorious drinker. With his dashing looks and one who was not opposed to finding trouble, he was equally popular with women and men and was one of the most popular players in baseball for a short time at the peak of his career. As a young minor leaguer in California, Donlin asked a San Francisco Examiner employee to run a photograph of him in the paper, saying "I know I'll get a break. I know I'm going to be great." A month after Admiral George Dewey's victory at the Battle of Manila Bay, University of Oregon baseball coach Tom Kelly recalled Donlin using a bat that he had painted red, white and blue and named "Dewey."
In October 1914 Donlin married actress Rita Ross, known for her part in the musical comedy team, Ross & Fenton.
Mike Donlin