Henry W. Halleck

Just the first few paragraphs of Wikipedia's entry on the General.

Henry Wager Halleck (January 16, 1815 – January 9, 1872) was a United States Army officer, scholar, and lawyer. A noted expert in military studies, he was known by a nickname that became derogatory, "Old Brains." He was an important participant in the admission of California as a state and became a successful lawyer and land developer. Early in the American Civil War, he was a senior Union Army commander in the Western Theater and then served for almost two years as general-in-chief of all U.S. armies. He was "kicked upstairs" to be chief of staff of the Army when Lt. Gen. Ulysses S. Grant, Halleck's former subordinate in the West, whose battlefield victories did much to advance Halleck's career, replaced him in 1864 as general-in-chief for the remainder of the war.

Halleck was a cautious general who believed strongly in thorough preparations for battle and in the value of defensive fortifications over quick, aggressive action. He was a master of administration, logistics, and the politics necessary at the top of the military hierarchy, but exerted little effective control over field operations from his post in Washington, D.C. President Abraham Lincoln once described him as "little more than a first rate clerk."