About: http://webisa.webdatacommons.org/122792328

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	By the mid-1960s, treatment centers were established in virtually every region of the U.S., as well as in Canada and other industrialized nations.
http://www.w3.org/ns/prov#wasQuotedFrom	gmu.edu