Nevertheless, the geopolitical instability in North America resulting from the American Civil War led to increased nervousness on the part of British North American colonies, particularly wary of the large Union Army operating south of their borders. The demands for closer political and economic ties between colonies led to further calls for an "Intercolonial Railway". An 1862 conference in Quebec City led to an agreement on financing the railway with the Maritime colonies and Canada splitting construction costs and Britain assuming any debts, however the deal fell through within months.