Foxall was a skilled arms manufacturer who brought the latest cannon boring techniques over from England. For decades his Columbia Foundry in Washington was the nation’s largest and most sophisticated cannon producer, supplying more than ten thousand guns to the Army and Navy.

The Columbia Foundry occupied several buildings on the Potomac riverbank opposite the Three Sisters Islands. The location was ideal - pig iron arrived via the Potomac (later the C&O Canal), labor came from Georgetown, and water power came from the nearby Mill Creek (now referred to as Foundry Branch). Finished products were exported through the nearby Port of Georgetown.

The Columbia Foundry enjoyed a virtual monopoly until the other three so-called “Great Foundries” were established in Richmond, Pittsburg, and West Point. From 1801 to about 1809 Columbia received almost every federal contract for cannon and ordinance. At its peak capacity, the munitions plant was capable of producing about 300 heavy guns and 30,000 cannon balls per year.

The Columbia Foundry was nearly destroyed in 1814 when British redcoats burned the Capitol. The detachment of soldiers marching on Foxall’s cannon works turned back in the face of a massive thunderstorm. Foxall built Foundry United Methodist Church out of gratitude for this divine intervention.