On August 10, 1861 when the question of Missouri and possibly Kentucky remaining in the Union was in the balance.
The war being a scant 4 months old.
The Union loss at Bull Run on July 21st and a
CS Army threatening Washington in the east.
Both Armies (
CS & US) being trained and mustered in and largely untested in combat.
Was the failure to actively pursue and prosecute the Union retreat from the defeat at Wilsons Creek/Oak Hill (depending on the color of your sack coat or lack there of for you militia guys) a lost opportunity on the part of Confederates to strike a blow that would have brought Missouri into the
CS?
IMO had McCulloch not been reluctant to pursue and destroy the retreating Federal Force as Price was wont to do the way to
CS control of Missouri might well have been open.