On 21 April 1775 the House of Burgess­es ve­he­ment­ly protest­ed ac­tions tak­en by a group of roy­al marines led by Lieu­tenant Hen­ry Collins. Un­der or­ders from Gov­er­nor John Dun­more, the marines moved fif­teen half-​bar­rels of gun­pow­der stored in Williams­burg's pow­der mag­a­zine to the ship Fowey on the York Riv­er.

Al­though the re­moval was car­ried out in the ear­ly morn­ing hours, word of the marines' ac­tion quick­ly spread through­out the town. Alarmed cit­i­zens de­mand­ed that Dun­more re­turn the sup­plies, but Pey­ton Ran­dolph, Robert Carter Nicholas, and May­or John Dixon calmed the pub­lic and re­quest­ed an ex­pla­na­tion from the gov­er­nor. Dun­more claimed he moved the pow­der to pro­tect the town from an im­pend­ing slave in­sur­rec­tion, and he promised to re­turn it if need­ed. The gov­er­nor lat­er ad­mit­ted that he feared an up­ris­ing among the colonists and that this anx­i­ety re­sult­ed in his or­der to re­lo­cate the pow­der.

Patrick Hen­ry raised 150 vol­un­teers from Hanover Coun­ty and threat­ened to march in­to Williams­burg un­less Dun­more gave back the gun­pow­der. The men agreed to re­turn to Hanover af­ter the gov­er­nor paid Hen­ry £350 as re­im­burse­ment for the seized pow­der. The sit­u­a­tion con­tin­ued to de­te­ri­o­rate, and on June 8 Dun­more left the gov­er­nor's palace for the Fowey. This, along with the en­su­ing war, end­ed British rule in Vir­ginia.

Al­though a land­mark in the his­to­ry of the Amer­i­can Rev­o­lu­tion, the pow­der mag­a­zine in Williams­burg has a sto­ry that be­gins years ear­li­er. In 1714, Gov­er­nor Alexan­der Spotswood and the Gen­er­al As­sem­bly agreed to erect a struc­ture to store mil­i­tary sup­plies giv­en to the colony by Queen Anne. The pow­der mag­a­zine was com­plet­ed by 1716, with a pro­tec­tive brick wall and guard house added in 1755. Us­es for the mag­a­zine var­ied through­out the years, in­clud­ing a mar­ket place, church, and stor­age space for mil­i­tary sup­plies dur­ing the Rev­o­lu­tion­ary War, the War of 1812, and the Civ­il War. When the his­toric struc­ture was pur­chased by the As­so­ci­a­tion for the Preser­va­tion of Vir­ginia An­tiq­ui­ties (AP­VA) in 1889, it had re­cent­ly been used as a liv­ery sta­ble and was in per­il of be­ing lost. The struc­ture was re­stored with help from the AP­VA and Colo­nial Williams­burg. To­day, the pow­der mag­a­zine serves as an ex­hib­it space for Colo­nial Williams­burg.