Answer the following question: Alexander Milne Calder (August 23 1846 June 4 1923) was a Scottish American sculptor best known for the architectural sculpture of Philadelphia City Hall. Both his son Alexander Stirling Calder and grandson Alexander Sandy Calder became significant sculptors in the 20th century. Given a list of categories: company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work, what category does the paragraph belong to?
Answer:
Artist