Gardiner was born September 16, 1839 in Gloucester, Virginia.
Little is known of his childhood except that he was born a free man. He enlisted at age 24 and listed his occupation as “oysterman.”
Following his tour of duty he moved to Ottumwa, Iowa, and married Helen Slaughter.
He began a Catholic ministry to the black communities across the nation, while supplementing his income as a barber. In his later years he married Emma Owens.
The family moved to Burlington, Iowa, and Peoria, Illinois.
He died September 29, 1905, at Clark's Summit, Pennsylvania.
He is buried in Calvary Crest Cemetery, Ottumwa, Iowa.