MAINE.--By that time Maine, which belonged to Massachusetts, had obtained leave to frame a constitution, and applied for admission as a free state. This afforded a chance to preserve the balance of states in the Senate, and Congress accordingly passed at the same time two bills, one to admit Maine as a free state, and one to authorize Missouri to make a proslavery constitution. THE MISSOURI COMPROMISE, 1820.--The second of these bills embodied the Missouri Compromise, or Compromise of 1820, which provided that in all the territory purchased from France in 1803 and lying north of the parallel 36° 30' there never should be slavery, except in Missouri (map p. 279). [16] This Compromise left a great region from which free states might be made in future, and very little for slave states. We shall see the consequences of this by and by. EXPLORATION OF THE WEST.--West of Missouri the country was still a wilderness overrun by Indians, and by buffalo and other wild animals. Many believed it to be almost uninhabitable. Pike, who (1806-7) marched across the plains from St. Louis to the neighborhood of Pikes Peak and on to the upper waters of the Rio Grande, and Long, who (1820) followed Pike, brought back dismal accounts of the country. Pike reported that the banks of the Kansas, the Platte, and the Arkansas rivers might "admit of a limited population," but not the plains. Long said the country west of Council Bluffs "is almost wholly unfit for cultivation, and of course uninhabitable by people depending on agriculture," and that beyond the Rockies it was "destined to be the abode of perfect desolation." [Illustration: BUFFALO RUNNING AWAY FROM A PRAIRIE FIRE.] THE GREAT AMERICAN DESERT.--This started the belief that in the West was a great desert, and for many years geographers indicated such a desert on their maps. It covered most of what is now Nebraska, Kansas, and Oklahoma, and parts of Texas, Colorado, and South Dakota. One geographer (1835) declared, "a large part maybe likened to the Great Sahara or African Desert." THE NORTHWESTERN BOUNDARY.--When Louisiana was purchased in 1803 no boundary was given it on the north or west. By treaty with Great Britain in 1818, the 49th parallel was made our northern boundary from the Lake of the Woods to the summit of the Rocky Mountains. [17] THE OREGON COUNTRY.--The country west of the sources of the Missouri River and the Rocky Mountains, the region drained by the Columbia, or as it was sometimes called, the Oregon River, was claimed by both Great Britain and the United States. As neither would yield, it was agreed that the Oregon country should be held jointly for a time. [18]