A long and bitter strife now ensued between the two British companies. It even assumed the magnitude of civil war, and finally resulted in a frightful massacre of unoffending colonists. The British government interfered and forced the rivals into court, where they were brought to the verge of ruin by protracted litigation. A compromise was at last effected in 1821 by an amalgamation of the two companies under the name of the older rival. But in the meantime a large part of their best fur country had been lost. In 1815 the government of the United States excluded British traders from its territory east of the Rocky Mountains. To the west of this limit, however, the amalgamated company easily forced all its rivals from the field. No American fur company ever attained the splendid organization, nor the influence over the Indians, possessed by the Hudson's Bay Company. At the time of which we write it was master of the trade in the Columbia River valley, and the eastern limit of its operations within the territory of the United States was nearly coincident with the present western boundary of the Yellowstone Park. The second of the great companies to which reference has been made was the American Fur Company. It was the final outcome of John Jacob Astor's various attempts to control the fur trade of the United States. Although it was incorporated in 1809, it was for a time overshadowed by the more brilliant enterprises known as the Pacific Fur Company and the Southwest Fur Company. The history of Mr. Astor's Pacific Fur Company, the dismal experiences of the Astorians, and the deplorable failure of the whole undertaking, are matters familiar to all readers of Irving's "Astoria." The other project gave for a time more substantial promise of success. A British company of considerable importance, under the name of the Mackinaw Company, with headquarters at Michilimacinac, had for some time operated in the country about the headwaters of the Mississippi now included in the states of Wisconsin and Minnesota. Astor succeeded in forming a new company, partly with American and partly with Canadian capital. This company bought out the Mackinaw Company, and changed the name to South-west Fur Company. But scarcely had its promising career begun when it was cut short by the War of 1812.