Porter spent decades trudging through Portland neighbourhoods selling J R Watkins products, determined to make his way through life independently despite physical challenges.
The Oregonian newspaper originally wrote about him at age 63, bringing him celebrity.
Porter had cerebral palsy, and spoke and walked with great difficulty. When he was young, the state considered him unemployable and suggested disability payments. He refused.
For years, he was Watkins' top retail salesman in a four-state region.
His story made its way to Reader's Digest and ABC's "20/20."
The Oregonian reports, Porter went to the hospital Tuesday with stomach pain and died of an infection.