The Civil War career of the much-maligned Union commander in chief and chief of staff, Henry W. Halleck, was summarized by Secretary of the Navy Gideon Welles as he "originates nothing, anticipates nothing. . . . takes no responsibility, plans nothing, suggests nothing, is good for nothing." This harsh assessment was shared by many but is really unfair.

The New York native and West Pointer (1839) had been posted to the engineers and earned a brevet in Mexico. He also worked on fortifications, taught at the academy, and studied the French military. His writings included: Report on the Means of National Defense, Elements of Military Art and Science, and a translation of Henri Jomini's Vie Politique et Militaire de Napoleon. Due to his scholarly pursuits he became known as "Old Brains," but this sobriquet became derogatory during the Civil War.

Resigning as a captain in 1854, he became highly successful in the San Francisco law profession and helped frame the state's constitution. He maintained his interest in martial affairs through the militia and was recommended by Winfield Scott for a high post at the outset of the Civil War.

His assignments included: major general, USA (August 19,1861); commanding Department of the Missouri (November 19,1861 - March 11, 1862); commanding Department of the Mississippi (March 13 - September 19, 1862); commander in chief (July 11, 1862 - March 12,1864); chief of staff (March 12,1864-ca. April 16, 1865); commanding Department of Virginia and Army of the James (April 16-June 28, 1865); and commanding Military Division of the James (April 19 - June 27, 1865).

Succeeding John C. Fremont at St. Louis, he straightened out the mess that had been left behind. After Grant, his subordinate, had captured Forts Henry and Donelson, Halleck was rewarded with command of all the forces in the West. His enlarged command won victories at Pea Ridge, Island #10, and Shiloh. Taking immediate command of his three united field armies after the latter battle, he proved to be an incapable field commander in his only campaign. The advance on Corinth, Mississippi, was so slow that the Confederates were able to withdraw at their leisure; Halleck was advancing at a rate of about one mile per day and then entrenching.

Made commander in chief shortly thereafter, he displayed tremendous administrative abilities, but many of his subordinates complained that he never gave adequate indications of what he wanted them to do or kept them informed of what other field leaders were doing. Halleck was also noted for a tendency to blame others for failures and was deeply resented by most top generals. When Grant took over as commander in chief, Halleck became the army's staff head and proved highly capable, if unpopular.

At the end of the war he commanded in Virginia and later on the Pacific. He died while heading the Division of the South at Louisville, Kentucky.