I'm wondering if Southern senators/congressmen made special appropriations or if Southern-leaning Generals transferred weapons/etc to Southern states in the years preceding the war. If yes, did it have any real impact on the early course of the war?
Yes. Toward the end of Buchanan's administration, Secretary of War John Floyd was accused - with some grounds - of funneling arms and ammunition to arsenals in the South which would shortly be seized by the Confederacy. He resigned in late December and went south, where he was commissioned as a Confederate general. Later, at Fort Donelson, he would flee rather than let himself be captured by Grant's army and perhaps be tried for treason.