About: http://webisa.webdatacommons.org/277042308

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	Although slavery was legal in many countries, the international slave trade had been banned by laws and treaties in nations such as Great Britain, Spain, the Netherlands, and the United States.
http://www.w3.org/ns/prov#wasQuotedFrom	si.edu