In 1964, British sociologist Ruth Glass was seeking a word for a phenomenon she observed in London's Islington neighborhood: creative young professionals were showing an interest in the historic homes that had, in the post-war years, become the domain of working class immigrants. The word Glass chose, which turns 50 this year, is one we know well: gentrification. Curbed National traces the history of the word and the idea of gentrification, from the "people with cultural capital" who began to "appreciate the urban environment" in the 1950s and 1960s to the many more confusing uses of the term today. [Curbed National]