At the outbreak of war, he joined the Confederate forces under General Thomas Green, and fought at the Battle of Lexington before being sent back by General Sterling Price to recruit in Northeast Missouri with Joseph C. Porter in the spring of 1862.
At the outbreak of the war, McCullough joined the Confederate forces under General Thomas Green. He took part in the Battle of Lexington, before being sent by General Sterling Price to recruit in northeastern Missouri with Joseph C. Porter in the spring of 1862.