Before approving McClellan’s plans for the Peninsula Campaign, U.S. president Abraham Lincoln insisted his general leave behind troops under Union general Irvin McDowell for the protection of Washington, D.C., as well as a possible strike against Richmond from the north. Stonewall Jackson’s soldiers in the Valley were charged with preventing McDowell from reinforcing McClellan, and toward that end, Jackson did his best to keep his army situated between McDowell and McClellan. In the meantime, Lincoln worried that it was dangerous for a Confederate force such as Jackson’s to roam free in the Shenandoah Valley, shaped as it is like a dart aimed at the U.S. capital. The president looked to General McDowell, and additional Union troops under Nathaniel P. Banks and John C. Frémont, to prevent Jackson from either attacking Washington or defending Richmond.