Very interesting John. I have run into Missourians nearly every place I`ve lived, especially Texas, Oklahoma & Montana. Missourians were early settlers in all those states.

"Migration patterns" Yes my ancestors came out of Caswell Co NC (1825) and Bourbon Co KY (1849).. Monroe County history claimed most of the early settlers came up the Mississippi River to New London (or Hannibal) then followed Salt River...but...when I started researching I found the first settlers in my family crossed the Mississippi just South of Stlouis then came up the Missouri River to Glasgow (Howard Co) and first settled there in what later (1829) became Randolph Co...moving to what became Monroe Co before 1831 (Jackson Twp in named after my gg grandpa)

One published account says they left NC in October and arrived in Howard Co on Jan 1st (a party of 60) I thought that would have been a poor choice of season to travel but they said the reason was in order to cross the rivers on the ice.
Must of had colder winters back then..`cause I lived in Hannibal for 12 yrs (1980-1992) and only saw the Miss. River frozen solid enough to cross on the ice once.

To get OT I will add that all my ancestors were living in Missouri before the WBTS...None fought for the Union, but one or two did just sorta "hide & watch"...Two relatives died in the war (one of typhoid fever and one KIA at Lone Jack)