Elijah Leonard’s memoir recounts his role in the Demarest rescue: https://archive.org/details/honorableelijahl00leon
John Farrell’s Ph.D. Dissertation provides references to the relevant Chatham Planet articles dealing with the Demarest rescue: https://ruor.uottawa.ca/handle/10393/21319
Chatham Planet articles:
Sample of American Coverage of the Event:
Keowee Courier. October 16, 1858 Arkansas True Democrat. November 3, 1858 Anti-Slavery Bugle. October 16, 1858 Cleveland Morning Leader. November 29, 1858 Nashville Patriot. October 7, 1858 New Orleans Daily Crescent. October 7, 1858
Sample of British Coverage of the Event:
Map of published stories of the Chatham event: Coming Soon
This map shows all of the newspapers in the USA and in the British Isles which reported on the Demarest incident in Chatham. This event was reported by newspapers in 5 different countries, which highlights the importance and rarity of the event. The vast majority of these articles were published in October 1858, one month after the incident.