The Puzzle 1 answer turns out to be incomplete! From The Rashness of That Hour:
After reporting for duty [to the First US Cavalry] at Jefferson Barracks, Missouri, [future general Alfred] Iverson settled quickly into military life. He served with a group of officers destined to become household names during the next decade. Colonel Edwin V. Sumner commanded the regiment, with field officers Lt. Col. Joseph E. Johnston, Maj. William H. Emory, and Maj. John S. Sedgwick. Captain George B. McClellan served as one of the senior captains. The junior officers included future Confederate generals James Ewell Brown Stuart, William S. Walker, George T. "Tige" Anderson, Robert S. Garnett, William N. R. Beale, George H."Maryland" Steuart, James Mclntosh, Robert Ransom, and Lunsford L.Lomax.Cosmic!