I literally just stumbled across this circular. Across the top you will see the names of major moderate Republican's in St Louis in Feb 1861. Just reading the introduction underscores the political intrigue and vitrolic nature of pro-Union Republicans at the time.

http://cdm.sos.mo.gov/cdm4/document.php?CISOROOT=/CivilWar&CISOPTR=17918&REC=20&CISOSHOW=17917

John R.