Plankinton Statue dated to 1883
Date of Plankinton statue is in dispute. Many sources claim the statue is 144 years old (1868), but it is more likely to have been created during the mid 1880’s when the sculptor, R. H. Park, was in Milwaukee creating two other public monuments. Or it could have been created later, after John Plankinton’s death in 1891.
I’ve linked to an article that claims Elizabeth Plankinton, John’s daughter, discovered the sculptor in Florence, Italy, and dates an R.H. Park bust (not a full-length statue) of Plankinton to 1883. Since Elizabeth was born in 1853 and would have been only 15 years old in 1868, this casts doubt on its age being 144 years.
Another source hints that it could be even younger. I found a paragraph about the Plankinton House in an 1892 publication, Milwaukee’s Great Industries that implies that the bronze statue was “recently” placed after Plankinton’s death as a “tribute to the memory of the man who made the house popular.”
Stay tuned as I seek the definitive source!
RPJ Histories - Ruth Page Jones 
Was Elizabeth Plankinton engaged to R.H. Park? I read some new stories that said he ran away with a dancer and that is why she never lived in the house her father built her.