In 1909 the copyright law stated that a copyright was for a period of 28 years. This could be renewed for an additional 47 year period, making a total of 75 years of copyright protection.
In 1976 the copyright law was changed. Copyrights are now for the period of the creator's life plus 50 years. Anything copyrighted before 1976 falls under the 1909 law.
On March 25, 1998 the bill H.R. 2589 was passed which extends copyright
terms another 20 years to 95 years.
This means that anything published prior to 1903 has no further copyright protection, and can be published freely by anyone. The same would apply to photostated copies of that material, or reprints of books originally published prior to that time. The mere reprinting of material does not extend the copyright beyond the 95 year period, unless additional material has been added, and even then only the additions may be copyrighted.