The Slavery started thousands years ago, but it seems to me that is still exist!! Are they any differences between 10th and 21st Century???
Links: http://www.ashbrook.org/library/18/jefferson/declaration.html
http://www.liverpoolmuseums.org.uk/ism/learning/slavery-today/about-slavery/outlawing-slavery.aspx
http://www.liverpoolmuseums.org.uk/ism/learning/slavery-today/about-slavery/outlawing-slavery.aspx
http://en.wikipedia.org/wiki/Thirteenth_Amendment_to_the_United_States_Constitution
http://en.wikipedia.org/wiki/Slavery#Present_day
http://www.guardian.co.uk/society/2011/nov/16/young-jobseekers-work-pay-unemployment
http://www.newint.org/features/2001/08/05/facts/
http://docsouth.unc.edu/neh/chron.html
http://www.huffingtonpost.com/2011/01/17/i-have-a-dream-speech-text_n_809993.html
http://www.monticello.org/site/jefferson/quotations-slavery-and-emancipation
http://en.wikipedia.org/wiki/United_States_Declaration_of_Independence