He was also active in promoting equal rights for African-Canadians and was involved with the National Unity Association (NUA) in sit-ins in Dresden, Ontario restaurants that refused to serve blacks. Armstrong travelled to Dresden following the activities of Hugh Burnett and the NUA—the NUA had been urging the local town council (unsuccessfully) to create laws that would put an end to discrimination against blacks in the town.
He was a supporter of equal rights for African Canadians and participated in sit-ins at restaurants in Dresden, Ontario that refused service to black people. Armstrong traveled to Dresden after Hugh Burnett and the National Unity Association (NUA) had been urging the local council to pass laws against discrimination against blacks.