The subsequent military career of Garfield fully sustained its brilliant beginning. With his new commission he was assigned to the command of a brigade in the Army of the Ohio, and took part in the second and decisive day's fight in the great battle of Shiloh. The remainder of the year 1862 was not especially eventful to Garfield, as it was not to the armies with which he was serving. His practical sense was called into exercise in completing the task assigned him by General Buell, of reconstructing bridges and reëstablishing lines of railway communication for the army. His occupation in this useful but not brilliant field was varied by service on courts-martial of importance, in which department of duty he won a valuable reputation attracting the notice and securing the approval of the able and eminent Judge Advocate General of the Army. That of itself was warrant to honorable fame; for among the great men who in those trying days gave themselves, with entire devotion, to the service of their country, one who brought to that service the ripest learning, the most fervid eloquence, the most varied attainments, who labored with modesty and shunned applause, who, in the day of triumph, sat reserved and silent and grateful--as Francis Deak in the hour of Hungary's deliverance--was Joseph Holt, of Kentucky, who, in his honorable retirement, enjoys the respect and veneration of all who love the Union of the States. Early in 1863 Garfield was assigned to the highly important and responsible post of chief of staff to General Rosecrans, then at the head of the Army of the Cumberland. Perhaps in a great military campaign no subordinate officer requires sounder judgment and quicker knowledge of men than the chief of staff to the commanding general. An indiscreet man in such a position can sow more discord, breed more jealousy, and disseminate more strife, than any other officer in the entire organization. When General Garfield assumed his new duties, he found various troubles already well developed and seriously effecting the value and efficiency of the Army of the Cumberland. The energy, the impartiality, and the tact with which he sought to allay these dissensions, and to discharge the duties of his new and trying position, will always remain one of the most striking proofs of his great versatility. His military duties closed on the memorable field of Chickamauga, a field which, however disastrous to the Union arms, gave to him the occasion of winning imperishable laurels. The very rare distinction was accorded him of a great promotion for his bravery on a field that was lost. President Lincoln appointed him a major-general in the army of the United States for gallant and meritorious conduct in the battle of Chickamauga.