=Literature.=--_Boone_, Education in the United States; _Williams_, History of Modern Education; _Barnard_, _American Journal of Education_; _Horace Mann_, Annual Reports; United States Commissioners Reports, especially the more recent ones. Each state in the United States has its own independent system of education; there is no national system. In 1867 Congress established a National Bureau of Education, the function of which is "to collect statistics and facts showing the condition and progress of education in the several states and territories, and diffuse such information respecting the organization and management of schools and school systems and methods of teaching as shall aid the people of the United States in the establishment and maintenance of efficient school systems, and otherwise promote the cause of education throughout the country." The bureau issues an annual report, which is replete with information concerning the educational interests of our own and other lands. The United States government has given vast tracts of the public domain, as well as large sums of money, to the various states, out of which have been created, in some cases, large school funds which yield a permanent income.[181] Up to 1876 the United States had granted nearly eighty million acres of land for educational purposes. The Bureau of Education is obliged to rely on such statistics as its correspondents are willing to give, yet its work has been so valuable, its information so extensive and accurate, and its educational purpose so high, that cordial cooeperation is generally given. This annual report is the finest issued by any nation in the world.[182] THE STATE SYSTEMS =Administration.=--At the head of each state school system, there is an executive officer usually called the State Superintendent of Public Instruction. He is chosen for from two to five years, sometimes by popular vote, sometimes by the joint houses of the Legislature, sometimes by the State Board of Education, and in some cases is appointed by the governor. His duties are to make reports, to examine teachers, to inspect schools, to distribute school moneys, to hear appeals in school matters, and to have general oversight of the educational interests of the state. In some states there is a State Board of Education that cooeperates with the State Superintendent. The interests of education seem to be best conserved when there is a non-partisan State Board of Education, which appoints the executive officers and has general charge of the schools.