Mezue ahịrịokwu na-esonụ: Hardee gbara arụkwaghịm n'ọrụ ya na United States Army na Jenụwarị 31, 1861, mgbe obodo ya bụ Georgia kewapụrụ onwe ya na Union. O sonyeere ndị agha Confederate States dị ka onye ọchịagha na Machị 7 ma nye ya iwu nke Fort Morgan na Gaines na Alabama. E mechara bulie ya n'ọkwa Brigadier General (June 17) na Major General (October 7). Ka ọ na-erule Ọktoba 10, 1862, ọ bụ otu n'ime ndị isi ndị agha mbụ nke Confederate. Ọrụ mbụ ya dị ka ọchịagha bụ ịhazi otu ndị agha nke ndị agha Arkansas ma ọ masịrị ndị ikom ya na ndị ọrụ ibe ya site na idozi nsogbu ọkọnọ siri ike na maka ọzụzụ zuru oke o nyere ndị agha ya. Ọ natara aha ya, "Old Reliable", mgbe ọ nọ n'ọchịchị a. Hardee rụrụ ọrụ n'Arkansas ruo mgbe a kpọrọ ya ka ọ sonye na ndị agha General Albert Sidney Johnston nke Central Kentucky dị ka onye isi ndị agha. Johnston ga-esi na Kentucky na Tennessee, banye na Mississippi, tupu ịmalite mwakpo mberede na
Agha Shiloh n'oge opupu ihe ubi nke afọ 1862. E merụrụ Hardee ahụ n'ogwe aka n'April 6, 1862, n'ụbọchị mbụ nke agha ahụ. E gburu Johnston na Shiloh na ndị agha Hardee sonyeere ndị agha General Braxton Bragg nke Tennessee tupu Siege nke Corinth, Mississippi, ruo mgbe Onye isi ngalaba PGT Beauregard wepụrụ obodo ahụ wee laghachi Tupelo. A dochiri Beauregard site na Bragg, onye mechara kwaga ndị agha ya na Chattanooga tupu ọ banye na Confederate Heartland Offensive na Kentucky. Mgbasa ahụ kwụsịrị na Agha nke Perryville na Ọktoba 1862, ebe Hardee nyere iwu na Left Wing nke ndị agha Bragg.