He would enroll at the military college of West Point where he would graduate second of his class. 1During the graduation it was learned that Lee did not receive a single demerit during his four years at West Point. Following graduation, Lee was commissioned as an officer and saw action in the Mexican War under the command of General Winfield Scott. Lee saw combat at the siege of Veracruz, an important seaport needed by the Americans in their war with Mexico. 2 For his leadership during the siege General Scott quoted saying Lee was "the very best soldier I saw in the field". Following the war, Lee became the superintendent of his alma mater West Point. This title would be held until permission to be transferred was granted by then Secretary of War Jefferson Davis. Following his transfer, the raid on Harpers Ferry by abolitionist John Brown occurred and Lee was tasked to hunt down Brown and his men responsible for the raid. 3Accompanying Lee on this mission was J.E.B Stuart, who would later on become one of Lee's most trusted officers in the Confederate Army.
With the Civil War commencing with the bombardment of Fort Sumter, Lee became the man on the fast track to becoming general of all the Union troops. After turning down the position offered by his old commanding officer General Scott, Lee wrote back asking to not be in charge of troops fighting against his home state of Virginia. This lead to uproar by Scott, calling for Lee's resignation from the military. Following this, Lee sent in his resignation of 3command of the first cavalry regiment to Secretary of War Simon Cameron. He would then return to his home state of Virginia and become the commander and chief of the army and naval forces of Virginia. 4 On May 14, 1861 he became brigadier general, the highest rank allowed at the time. This title would later be promoted to full general. .
Lee's first position in the Confederacy would be to halt the Union advance on the western border of Virginia.