Sonora Smart Dodd and her five siblings were raised by their father after their mother died.
She got the idea to recognize her dad during a service at Central Methodist Church in Spokane, Wash.
"My Grandmother, oversees the church Sunday morning. It's the first Sunday they were celebrating Mother's day, and she thought about her own father and what he'd done to raise his family single handed after her mother died, and she thought, 'Well, why don't they honor fathers?' because her father's done everything for her and her brothers," said Dodd's granddaughter Barbara Hillerman.
Dodd shared the idea with her minister and Spokane's city leaders.
Eventually, it led to the official holiday, which is now recognized in more than 50 countries.