“The Most Propitious Time…for the Confederate Army to Enter
Maryland:” Robert E. Lee’s Decision to Invade the North in
September 1862 By Gary W. Gallagher In taking his army across
the Potomac River in early September, Lee had in mind strategic,
logistical, and political factors. He believed that the soldiers
of McClellan and Pope “lay weakened and demoralized” in the
vicinity of Washington, D.C., and he sought to maintain
aggressive momentum rather than assume a defensive position and
allow the Federals to muster their superior strength to mount
another offensive. If he remained in Virginia, Lee would be
forced to react to Union movements, whereas in Maryland or
Pennsylvania he would hold the initiative. Lee believed he could
easily flank the enemy by crossing the Potomac upriver from
Washington and marching the Army of Northern Virginia through
Maryland. A short thrust into Union territory would not be
enough; a protracted stay would be the key to Confederate
success. Lee hoped to keep his army on United St