Treaty No. 7 was the last of the numbered treaties negotiated and signed during the 1870s. The treaty covers the southern part of present-day Alberta. From the government's perspective, the need for Treaty Seven was immediate and simple. As part of the terms of bringing British Columbia into Confederation in 1871, the Canadian government had promised to build a trans-continental railway within ten years. Such a line would have to traverse the newly- acquired western territories, through land still nominally in control of Indian tribes. Huge land concessions would need to be offered to the company building the railway and later, the existence of the line would encourage large-scale immigration to the western prairies.