Jubal Early’s Raid

In July 1864 Jubal Early and his men approached the outskirts of Washington, DC, tested the Union defenses north and northwest of the capital, and chose to withdraw rather than to launch an assault.  He he arrived a day or so earlier, perhaps he would have decided differently, but his advance on Washington was delayed when Lew Wallace and a makeshift defense force put up a sharp little fight at Monocacy, Maryland, close to Frederick.

What do you think was the impact of Early’s July raid?  What could have happened?  Was it a sideshow, or something more?