was he a part of any war?
Yes, Mexican–American War.
Jefferson Davis
In 1846 the Mexican–American War began. Davis raised a volunteer regiment, the Mississippi Rifles, becoming its colonel under the command of his former father-in-law, General Zachary Taylor. 
president of the south in the civil war Jefferson Finis Davis where is he from? Fairview, Kentucky. when did he become president? 1861 was he into military? Yes, he was assigned to the 1st Infantry Regiment.
wiki:7742614
Jefferson Davis [SEP] Mexican–American War
In 1846 the Mexican–American War began. Davis raised a volunteer regiment, the Mississippi Rifles, becoming its colonel under the command of his former father-in-law, General Zachary Taylor. On July 21 the regiment sailed from New Orleans for Texas. Colonel Davis sought to arm his regiment with the M1841 Mississippi rifle. At this time, smoothbore muskets were still the primary infantry weapon, and any unit with rifles was considered special and designated as such. President James K. Polk had promised Davis the weapons if he would remain in Congress long enough for an important vote on the Walker tariff. General Winfield Scott objected on the basis that the weapons were insufficiently tested.