The refugee slaves who settled in Canada did so primarily in South Western Ontario, with significant concentrations being found in Amherstburg, Colchester, Chatham, Windsor, and Sandwich. Run-away slaves tended to concentrate, partly to provide mutual support, partly because of prejudices, and partly out of the fear of American bounty hunters crossing the border. The run-away slaves usually arrived destitute and without any assets, had to work as laborers for others until they could save up enough money to buy their own farms. These settlements acted as centres of abolitionist thought, with Chatham being the location of abolitionist John Brown's constitutional convention which preceded the later raid on Harper's Ferry. The first newspaper published by a black woman was founded in North Buxton by the free Black Mary Ann Shadd which pressed for Black emigration to Canada as the best option for fleeing African Americans. The settlement of Elgin was formed in 1849 with the royal assent of Governor-General of the time James Bruce as a settlement for Black Canadians and escaped slaves based upon social welfare and the prevention of moral decay among the Black community there. Led by the Elgin Association and preacher William King, the settlement flourished as a model of a successful predominantly African settlement which held close to 200 families by 1859.