'Minnesota nice'

Has anyone else heard this term before? I heard it when I was listening to this weird mexican rap o.O I asked my mom "wtf did she just say Minnesota nice?" my mom said "you haven't heard that before" then she said "many people say that people from minnesota are nice and its true trust me, Once I went to Chicago and I came across some very rude people" some shiz like dat so i'm wondering if that has any truth behind it all? Sure I went to Florida and walked past a few crude people but some are really nice.