▁they ▁" har bor ed ▁ 7 5 ▁percent ▁of ▁all ▁slaves ▁passing ▁through ▁Boston ." ▁Following ▁the ▁passage ▁of ▁the ▁F ug itive ▁S lave ▁Act ▁in ▁ 1 8 5 0 , ▁she ▁managed ▁and ▁operated ▁Boston ' s ▁main ▁Under ground ▁Rail road ▁operations , ▁and ▁was ▁key ▁to ▁leading ▁people ▁through ▁Boston ' s ▁tunnel ▁system . ▁Har ri et ▁along ▁with ▁her ▁husband ▁were ▁pra ised ▁by ▁fellow ▁abol ition ists ▁Frederick ▁Doug lass ▁and ▁William ▁Lloyd ▁G arrison ▁for ▁their ▁significant ▁efforts ▁in ▁a iding ▁escaped ▁black s . ▁One ▁of ▁the ▁more ▁frequent ▁visitors ▁to ▁the ▁Hay den ' s ▁household ▁during ▁there ▁ante bell um ▁activ ist ▁years ▁was ▁John ▁Brown . ▁Between ▁ 1 8 5 7 ▁and ▁ 1 8 5 9 ▁Brown ▁visited ▁and ▁stayed ▁with ▁the ▁Hay dens ▁and ▁dis closed ▁his ▁plans ▁to ▁ra id ▁Har per ' s ▁Fer ry , ▁Virginia . ▁Har ri et ▁and ▁her ▁husband ▁helped ▁to ▁raise ▁money ▁in ▁support ▁of ▁Brown ' s ▁ra id . ▁It ▁was ▁also ▁rum ored ▁that ▁the ▁Hay dens ▁kept ▁bar rel s ▁of ▁gun pow der ▁in ▁their ▁home ▁and ▁threatened ▁to ▁light ▁it ▁if ▁anyone ▁attempted ▁to ▁take ▁an ▁escaped ▁slave ▁from ▁their ▁house . ▁ ▁Leg acy ▁ ▁Har ri et ▁Hay den ▁died ▁of ▁p neum onia ▁in ▁her ▁home ▁at ▁the ▁age ▁of ▁ 7 4 ▁in ▁ 1 8 9 3 . ▁Following ▁her ▁death , ▁Har ri et ▁Hay den