July 11, 1862
Ordered, That Major-General Henry W. Halleck be assigned to command the whole land forces of the United States as General in Chief, and that he repair to this capital as soon as he can with safety to the positions and operations within the department under his charge.
A. LINCOLN.
Abraham Lincoln, Executive Order—Making Henry W. Halleck General-in-Chief Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/202597