Sebulon (also written as Zebulon) Olson (1862-1933) was born in Sweden and emigrated in 1886. He was a hoisting engineer and probably worked on Nils I. Nelson's crew setting most of the marble. Olson and his wife Signe raised their family on St. Paul's East Side while he worked as a hoisting engineer. Hosting engineers were unionized in St. Paul during the Capitol construction and since Olson likely worked with union activist Nils Nelson, it is quite probable that Olson too was a union member.
Here is further information from his granddaughter (who seems to exagerate) via Zebulon's great granddaughters. (The family uses the "Zebulon spelling of his last name, though he spelled his name with an "S.")
"Zebulon Olson was a self-educated man, having no schooling and on his own at age 17. He set all the stones in the Minnesota State Capital Building. He had complete control of the [hoisting] machine and was paid $2.00 gold pieces for the work. He was a drinker, and although in his later years he spent a year with Alice and Oscar [Zebulon's son and daughter in law], he finally left and went downhill as an alcoholic, dying of stomach trouble.” The assertion that he died as a result of alcoholism is contested and not indicated in his obituary (shown on this page).
To read the transcript of an interview with Sebulon Olson's great granddaughters click here