_The Residence Requirement._--In the first place, all the states require residence for a specified period in the state and in the election district in which the voter exercises his privilege of voting. The purpose of this requirement is to confine the franchise to those who have become identified with the interests of the community, and to exclude outsiders or newcomers who are unfamiliar with local conditions and unacquainted with the qualifications of the candidates. The required length of residence in the state ranges from three months in Maine to two years in most of the Southern states, the more usual requirement being one year. The period of residence required in the county or election district is shorter, the most common requirement being three months in the county and one month in the election district. _Educational Tests._--In addition to this requirement, nearly one third of the states insist upon some kind of educational test. Connecticut in 1855 was the first state to require ability to read and write. Massachusetts followed her example shortly thereafter, and the precedent set by these two states was soon followed, with modifications, by California, Maine, Wyoming, New Hampshire, Delaware, and Washington. The adoption of the Fifteenth Amendment in 1870, which indirectly conferred the right to vote on the negro race, and the unfortunate results which followed the enfranchisement of the large mass of blacks in the South, led some of the Southern states to adopt educational and other restrictions to diminish the evils of an ignorant suffrage. Mississippi in 1890 took the initiative, and required ability either to read the constitution of the state or to understand it when read by an election officer. South Carolina followed her example in 1895, but with the modification that an illiterate person who was the owner of at least $300 worth of property should not be disfranchised. Louisiana, Alabama, North Carolina, Virginia, Oklahoma, and Georgia followed with restrictions based on similar principles. In several of these states, however, the educational qualification does not apply to those who were voters in 1867 (when the negro race was still unenfranchised), or to their descendants, or to those who served in the army or navy during the Civil War. But in 1915 the Supreme Court of the United States decided, in the case of Oklahoma, that these so-called "grandfather" provisions were unconstitutional. _Other Persons Excluded._--Most of the states deny the right to vote to convicted criminals, idiots, and insane persons; some, particularly those of the South, insist that the voter must have paid his taxes; some exclude vagrants, paupers, and inmates of public institutions.