The Indian Territory, as it is called, is a tract of country bounded on the south by the Red River, east by the States of Arkansas and Missouri, on the north and northeast by the Missouri and Punch Rivers, and west by the western limit of habitable country on this side of the Rocky Mountains. This has been purchased, at various prices, of the indigenous tribes. The soil is said to be most excellent, abounding in fine water, timber, mines of coal, iron, and lead; at the same time, it is the resort of numerous buffaloes, so that it seems well adapted for the purposes to which it is destined.

The plan adopted by the government has been by purchase to extinguish the Indian title to those lands which they leave, give them others within the new territory, transport them thither, and erect a portion of their dwellings, plough and fence a part of their fields, furnish them teachers in agriculture, and tools, horses, cattle, &c., build school-houses and provide instructors, and make arrangements for the support of those who have not the means at hand, at the outset, for this purpose.

By treaty, the lands are perpetually guarantied to them, and stipulations have been entered into, by which they receive annual sums of money, and other sums are also to be expended in useful articles, and for the purposes of education. Agents are stationed among them, who, as well as the teachers provided for them, make annual reports to the Commissioner of Indian Affairs, who includes these documents in his own annual report to Congress. Governments, properly constituted by themselves, are also guarantied to them, and it is understood to be the design to lead them to establish elective governments in each tribe, similar to our own State governments; all to be united in a kind of federal republic. Some of the tribes have adopted the preliminary measure, and have already made important advances towards civilization.

The relative position of the various tribes is as follows. Immediately on the Red River, beginning at the south, are the Chickasaws; then follow, in order, towards the north, the Choctaws, Seminoles, Creeks, Cherokees, Shawanese, Senecas, Quapaws, Oneidas and Tuscaroras, Piankeshaws and Weahs, Peorias and Kaskaskias-Shawanese, Kansas, Delawares, Kickapoos; then, north of these, the Omahaws and Otoes, Missouris, Pancas, and Pawnees; north of the Missouri, the Sacs and Foxes; and west of the Peorias and Oneidas are the Osages.

The Chickasaws have become, in a great degree, merged in the Choctaws. Their district, called the Chickasaw District, they purchased of the Choctaws for $530,000. By the treaty of 24th of May, 1834, it is provided, that $3,000 shall annually, for fifteen years, be expended, under the direction of the Secretary of War, for the education of the Chickasaws. They are a wealthy people, having invested nearly $2,000,000, from which they will soon receive interest; they have also a large fund for various objects, $10,000 of which is, at the present time, applied to the purposes of civilization.

The Choctaw country embraces 19,200,000 acres of good soil, and some 6,000,000 more of a poorer quality. This people are said now to be improving in civilization and comfort. They have many large farms, and much live stock, three flouring mills, ten or twelve cotton-gins, eighty-eight looms, and two hundred and twenty spinning-wheels.

The Choctaw nation has adopted a written constitution, similar to that of the United States. Their legislative body is said to transact its business with great decorum and propriety. Their journals are kept in the English language, but, in the progress of business, are also read off in the Choctaw. They have four judicial districts, and the usual officers of justice. They are likewise, says the agent among them, fast approaching to the division of lands, and carefully seize and destroy whisky illegally introduced among them. By the treaty of 1830, forty Choctaw youths are to be kept at school, under the direction of the president of the United States, for the term of twenty years. Also, the sum of $2,500 is to be applied for the support of three teachers of schools among them, for the same number of years. They have, likewise, a balance of $25,000 of unexpended annuities, which is to be applied to the support of schools at twelve different places; and, by the treaty of 1825, they have a further annuity of $6,000, for the support of schools.

There are among them, as appears from the last report of the Commissioner of Indian Affairs, fifteen teachers and four hundred and five scholars. The missions there are under the direction of the American Board of Commissioners at Boston, and in their last report they state that the churches have all been enlarged, the aggregate increase having been somewhat more than one hundred. The whole number now connected with five churches is four hundred and seventy-one. The number of Choctaws able to read is steadily increasing, and the demand for books is becoming greater every year.

The Creeks are not so well organized, in respect to their government, as the Choctaws or Cherokees. There are two bands or parties, one under McIntosh, the other under Little Doctor. The first of these brought from their former home their old laws; the latter have framed theirs since their removal. Both of them have their general councils, who combine the legislative, executive, and judicial departments in one. They own salt-springs, cultivate the ground, and follow other pursuits of civilization. Many of them, also, are said to have large stocks of cattle. Before the crops of 1837 had been gathered, it is stated that they had sold corn to the amount of upwards of $39,000, and that vast quantities then remained unsold; and even the emigrants, who arrived in the country during the winter and spring previous to the harvest of that year, broke the turf, fenced their fields, raised their crops for the first time, and sold their surplus of corn for $10,000. By the treaty of the 6th of March, 1832, it is stipulated that an annuity of $3,000 shall be expended by the United States, under the direction of the president, for twenty years, in the education of their children. Besides this, $1,000, by the treaty of the 14th of February, 1833, is to be annually expended, during the pleasure of Congress, for the same object. A great number of the Creeks, and of the Seminoles who are now merged in that tribe, died on the way, or shortly after their removal to the Indian Territory.

The Cherokees have probably made the greatest advances in civilization of any of the Indian nations on our western border. They own numerous salt-springs, which are worked by themselves, and in which they manufacture, it is said, one hundred bushels of salt, daily. They also own two lead-mines. The eastern portion of their country, which embraces the settlements, contains about 2,500,000 acres. They have a large stock of cattle, wagons, ploughs, looms, and spinning-wheels; their lands are well inclosed with rail-fences; and they have comfortable log-houses, with stone chimneys and plank floors, which are well furnished. They have, likewise, seven native merchants, and one regular physician.