Harry Milligan worked as the photographer at Manchester Central Library until his retirement in around 1968. He was instrumental in setting up the Manchester Region Industrial Archaeology Society in 1965. He volunteered at the North Western Museum of Science and Industry from 1968, assisting with reprographics requests. His knowledge of the history of photography in Manchester and the UK led to him taking on the role of Honorary Curator of Photography at the museum. He died in 1986.