Leslie C. Steen Monument, Allegheny Cemetery Leslie C. Steen died in 1867 at the age of 20, according to cemetery records. We may presume that this ponderous and weighty Gothic-classical monument was put up by his parents. Related posts Mount Lebanon Cemetery OfficeOffice, Mt. Lebanon CemeteryDr. G. T. Jacoby Mausoleum, Prospect Cemetery Author: Father Pitt Documenting his city since 1758.