Gilmor's Raid

Johnson's main cavalry force continued pressing Wallace's retreating Union troops, pursuing them into Cockeysville-Hunt Valley, Maryland, north of Baltimore, and then turned south destroying tracks and trestle bridges along the Northern Central Railway.

The second part of Johnson's cavalry simultaneously turned south and headed toward the prison camp at Point Lookout, Maryland at the confluence of the Potomac River and the Chesapeake Bay.

They first stopped at the General Store in Jerusalem Mill now popularly known as McCourtney's, capturing supplies and horses, and then arrived on the morning of July 11 at the Gunpowder River bridge, a railroad bridge near Magnolia Station, close to Joppa, Maryland, which belonged to the Philadelphia, Wilmington and Baltimore Railroad.

Gilmor's detachment then proceeded back through Green Spring Valley, to recover his prisoner, Gen. Franklin, who had escaped.

Field was leading Gilmor's advance guard and refused to pass under a Union flag on the Day residence.