Through the first week of June 1862, General Thomas J. "Stonewall" Jackson steadily fell back up the Shenandoah Valley, under pressure from two widely separated Federal columns. His monumental triumphs at Front Royal and Winchester, on May 23 and 25, had unhinged Unionist aspirations for control of the Valley, but now fresh Northern forces under John C. Fremont and James Shields pursued him in quest of revenge.
The towering, generally impassable, Massanutten massif played a key role in setting the stage, separating the Valley into two discrete halves for fifty miles. So did the two arms of the Shenandoah River, wending northward on either side of the big mountain, and only bridged infrequently. The disparate Federal commands allowed themselves to be separated by the Valley's topography. Shields moved through the smaller valley east of Massanutten; Fremont followed Jackson west of the mountain, and in direct contact.
Keeping Fremont and his troops from following close behind became an essential element for Jackson's success. If they arrived around Port Republic--south of the Massanutten--in time to collaborate with Shields, Jackson faced dire odds and the potential to be assailed from both sides.
On Sunday, June 8, Stonewall prepared for the church services he so much loved as quiet early morning light bathed his headquarters at the southern edge of Port Republic. Shields had not yet shown up from due north, and Confederate General Richard S. Ewell stood athwart Fremont's path at Cross Keys, a few miles from Port, down the Harrisonburg Road.
Dick Ewell's troops occupied an admirable defensive line above Mill Creek, in a region known as "Cross Keys" because of a nearby wayside tavern of that name. The Confederate line followed commanding ground, conveniently high enough above the stream to afford a magnificent field of fire onto any approaching foe. As though sculpted by nature for this military purpose, the high ground curled at its outer ends into a bit of an arc. An attacking enemy would expose his flanks to the edges of that crescent.
Unwilling to await an attack, and eager to close with the Yankees, General Isaac Ridgeway Trimble pushed his brigade of four regiments forward from the right (east) end of the Mill Creek line. Trimble's men—one regiment each from Georgia, Mississippi, Alabama, and North Carolina--found cover behind a fencerow, in a perfect position to ambush any Federals who pushed forward without appropriate caution. Enough vegetation grew around the fence to provide useful camouflage.
Precisely such an incautious advance as Trimble anticipated walked aimlessly into the Confederate deadfall, and paid a ghastly price for the error when Julius Stahel's brigade of New York a Pennsylvania troops moved toward Trimble's covert position, where they were gunned down at close range. Trimble's men, riding the crest of a wave of momentum generated by their repulse of the Stahel, pushed their advance right through the point where the Federal attack began.
With Fremont violently overwhelmed at a crucial point, and stymied everywhere else, Ewell had deftly accomplished his mission. Jackson would have the morning of June 9 in which to defeat the Federal force approaching Port Republic under Shields, without interference from the direction of Cross Keys.