You might be right - and I think there is a religious angle to it. Missouri had a lot of Catholics and Lutherans (still does). I think the clergy was hostile to loyalty oaths, being forced to disclose the names of slave-owning parishioners, and did not think highly of abolitionists. With the Catholics, the Archdiocese of St. Louis admits it had 3 bishops and numerous clergy who owned slaves: https://www.archstl.org/archdioceses-research-into-history-with-slavery-reveals-three-bishops-priests-as-slaveowners-6587 With the Lutherans, you had "Die Deutsche Evangelisch-Lutherische von Missouri, Ohio, und andern Staaten" with its headquarters and seminary located in St. Louis. (Today that is the Lutheran Church-Missouri Synod - the 9th largest protestant denomination in the country). These were mostly Saxon immigrants who predated the fourty-eighters and came to America for religious freedom (fleeing the Prussian Union where they were forced to worship with other protestants in Prussia). Really wanted to be left alone by government. Also super-triggered by abolitionists as shown by this piece written in 1863 by the first president of the denomination: http://www.lutherquest.org/walther/articles/cfw00002.htm If General Lyon had survived, I think he would have provided lots of fodder for the pulpit on Sunday mornings - thus increasing the likelihood of Missouri seceding.