John Brown was a white abolitionist from Kansas who planned to end slavery by training a group of men in "guerilla warfare". He planned to overthrow the American government to do so. He chose Chatham as the place to develop his military strategy and draw up the constitution the new government he hoped to form. In April 1858, he and 13 of his supporters arrived in Chatham. While Brown stayed at the home of James Bell, his supporters stayed at the Villa Mansion Hotel. Before the meetings, he drilled his men in Tecumseh Park under the guise that he had come to Chatham to form a new coloured lodge of the Masonic order. But soon after, a select group of friends was mailed letters asking them to attend his secret convention on Saturday May 8, 1858.
It was apparent what he was doing. At his first meeting in the British Methodist Church outlined his violent attack plans. The minister and some Chatham blacks were afraid of Brown's revolutionary plans and he was barred from holding his meetings there. Further meetings were held at the Princess St. School and the First Baptist Church. Here officers were elected to Brown's provisional government. Brown returned to Kansas and later found out that word had of the Chatham Convention had leaked. His raid was delayed for a year.
The raid on Harper's Ferry end in disaster as Brown was captured and arrested. The attack on October 16, 1859 became the first battle of the American Civil War. Brown was tried for conspiracy with slaves to rebel, treason, and murder. He was found guilty and hung late 1859.
Black Chathamites who supported John Brown included the Shadd family who loaned him their offices and printing press. Isaac Holden, captain of the Black Fire Brigade, and J.M Bell helped Brown by taking care of his mail. Isaiah Matthew, Edward Nolan, and Aaron Highgate, all went to Detroit on their way to join Brown's army, but turned back when they heard he had been captured. The only Black Canadian to take part in the raid was Osbourne Anderson who was friends with the Shadd family. He survived the raid, came back to Canada, and wrote a book with Mary Ann Shadd "A Voice From Harper's Ferry".