The phenomenon of Minstrel Shows is beyond controversial and apparently came late to Minnesota. Wikipedia gives the peak years of the genre as the 1830s and 1840s. A quick look at the Minneapolis newspaper archives shows that the first such show came to Minneapolis in 1867 and every year thereafter. 1890 appears to be the year that the shows ramped up in popularity locally, appearing in ads for several local theaters. The first shows were probably traveling shows featuring white men in blackface: the first troupe was called Duprez and Benedict.
As these faded, the genre continued as sketches on variety shows or as entertainment put on by schools and church groups. Push back finally came in the early 1960s; Minneapolis Tribune columnist George Grimm made it clear in his “I Like it Here” column of February 27, 1960, that they weren’t funny anymore, and no long acceptable. He reprinted the column verbatim on January 19, 1963, and vowed to keep reprinting it every two years. Wikipedia did point out that Archie Bunker appeared in blackface in 1975, but here in Minnesota, it appears that the odious olios had about a 100 year run. The last one I found in the paper was put on by a school PTA in Blaine in 1969.