http://www.nps.gov/brvb/historyculture/progressive.htm
http://www.cr.nps.gov/history/online_books/brvb/brown.pdf
http://www.history.com/this-day-in-history/13th-amendment-ratified - "Neither slavery nor involuntary servitude, except as a punishment for crime whereof the party shall have been duly convicted, shall exist within the United States, or any place subject to their jurisdiction."
http://library.thinkquest.org/TQ0312172/lincoln.html
http://americanhistory.about.com/od/usconstitution/a/14th-Amendment-Summary.htm
http://americanhistory.about.com/od/usconstitution/a/15th-Amendment.htm
http://www.lawnix.com/cases/plessy-ferguson.html
http://www.archives.gov/education/lessons/brown-v-board/timeline.html
http://www.cr.nps.gov/history/online_books/brvb/brown.pdf
http://www.history.com/this-day-in-history/13th-amendment-ratified - "Neither slavery nor involuntary servitude, except as a punishment for crime whereof the party shall have been duly convicted, shall exist within the United States, or any place subject to their jurisdiction."
http://library.thinkquest.org/TQ0312172/lincoln.html
http://americanhistory.about.com/od/usconstitution/a/14th-Amendment-Summary.htm
http://americanhistory.about.com/od/usconstitution/a/15th-Amendment.htm
http://www.lawnix.com/cases/plessy-ferguson.html
http://www.archives.gov/education/lessons/brown-v-board/timeline.html