On the night of August 13, 1813, 300 British troops marched toward Queenstown, where a large American militia force was said to be encamped. At Slippery Hill Farm, cornfields concealed a picket guard of 20 Queen Anne’s County, Maryland, militia troops watching for the advancing British Army. When the British encountered the picket guard, they fired and began the skirmish that became known as the Battle of Slipper Hill. Greatly outnumbered, the Americans used their knowledge of the landscape to take cover and fire repeatedly, causing panic in the British ranks. The horse of British Colonel Sir Sidney Beckwith was shot out from under him, leaving only Lieutenant Colonel Sir Charles Napier on horseback in the attempt to restore order. The American militia at Queenstown, under Major William H. Nicholson, was then able to retreat safely to Centreville.