Longtime Minnesota historian David Nystuen of Inver Grove Heights has died. He was 74 years old. According to an obituary place online, Nystuen was a huge advocate of Minnesota history and led the charge for each county in the North Star state to have its own historical society back in the 1980s. Each county does, and they remain in place today statewide. A memorial is set from 4 to 6 p.m. Friday, Sept. 6 at Cremation Society of Minnesota, located in Edina. David's complete obituary can be found here.