This gets a “wow.” Legislature dissolved by the Federal military. Things are bad in our country, but we haven’t gone that far...
...yet.
They picked quite a day for the action - the 80th anniversary of July Fourth, 1776. The rationale for it was that the free-state legislature was “extra-legal,” there being a pro-slavery legislature in place when the Topeka legislature was formed.
I just read in a biography of Jefferson Davis that, as Secretary of War, he reprimanded Sumner for the action. As a cabinet official Davis seems to have done a fairly decent job. Not counting his really juvenile feud with Winfield Scott.