Largely on the advice of several of Walker's supporters, including his brother Richard, President Jefferson Davis appointed him to the post of Secretary of War, though Walker was not personally known to Davis. He was energetic and confident in support of the Confederacy, but had no military training. The stress and difficulties of his cabinet position seriously affected his health. In March 1861, the Southern states that had seceded from the Union appointed special commissioners to travel to those other Southern states that had yet to secede. Walker was chosen as the commissioner from Alabama to the Tennessee Secession Convention, where he publicly read Alabama's Articles of Secession and tried to persuade Tennessee politicians to vote to do likewise.