Editing Solomon Northup (section)

===Last years===
Northup worked again as a carpenter after he moved back to New York. He became active in the abolitionist movement and lectured on slavery in the years before the [[American Civil War]].<ref name="Britannica" /><ref name="PS - freedom" /><ref>Fiske, David. ''Solomon Northup: His Life Before and After Slavery'', 2012, Appendix A.</ref> In the summer of 1857, he traveled to Canada to deliver a series of lectures; however, in [[Streetsville, Ontario]], a hostile crowd prevented him from speaking.<ref>{{cite news|title=Freedom in Canada| journal=Boston Herald|date= August 25, 1857|page= 2}}</ref>

After 1857, he was not living with family{{efn||name=lost}} and there was speculation by family, friends, and others that he was reenslaved.<ref name="Genz"/><ref>''American Union'' (Ellicottville, NY), November 12, 1858</ref><ref>{{cite book|author=Mann, E. R. |title=The Bench and Bar of Saratoga County|year= 1879|page= 153}}</ref><ref>{{cite news|title=Poor Sol. Northop|journal=Columbus (Georgia) Daily Enquirer|date= October 16, 1858|page= 2, citing the ''New York News''}}</ref> The 21st-century historians Clifford Brown and Carol Wilson believe it is likely that he died of natural causes,<ref name="Genz"/> because he was too old to be of interest to slave catchers.<ref name="wang"/>

According to John R. Smith, in letters written in the 1930s, his father Rev. John L. Smith, a Methodist minister in Vermont, had worked with Northup and former slave Tabbs Gross in the early 1860s, during the Civil War, aiding fugitive slaves on the [[Underground Railroad]].<ref name="Smithletter">"John R. Smith letter" (1930s), Wilbur Henry Siebert collection, Houghton Library, Harvard University {{cite web | url=http://oasis.lib.harvard.edu/oasis/deliver/~hou01912 | title=Wilbur Henry Siebert Collection | access-date=January 9, 2014 | archive-url=https://web.archive.org/web/20170403202928/http://oasis.lib.harvard.edu/oasis/deliver/~hou01912 | archive-date=April 3, 2017 }}</ref> Northup was said to have visited Rev. Smith after Lincoln's [[Emancipation Proclamation]], which was made in January 1863.<ref name="Smithletter"/>

There is no contemporaneous documentation of his death.<ref name="wang">{{cite web|last=Lo Wang|first=Hansi|title='12 Years' Is The Story of a Slave Whose End Is A Mystery| url=https://www.npr.org/blogs/codeswitch/2013/10/19/231520610/12-years-records-enslavement-but-how-does-the-story-end|work=NPR|access-date=January 7, 2014}}</ref><ref>{{Cite web|url=https://www.thenational.ae/lifestyle/death-of-solomon-northup-author-of-12-years-a-slave-still-a-mystery-1.277249|title=Death of Solomon Northup, author of 12 Years A Slave, still a mystery|website=The National|date=March 17, 2014|language=en|access-date=May 6, 2019}}</ref> Historians believe that he died in 1863 or 1864.<ref name="Smithletter"/><ref name="Britannica" /><ref name="PS - freedom" /><ref>{{Cite web |title=Solomon Northup |date=September 24, 2020 |language=en-us |url=https://www.biography.com/writer/solomon-northup |access-date=June 27, 2021}}</ref>