When a sword does not have any identifying makers or dealers marks, it is usually not possible to determine that it was Civil War period unless the model of the sword is such that it would have been available prior to the Civil War and thus possibly used in the Civil War. For example, a model 1840 Cavalry or Artillery saber - either for an officer or enlisted man would have most likely been available for the Civil War because most were made prior to or during the Civil War. Few were made after and the Civil War and the model changed in 1872. Other means of identifying a period for a sword is the blade width, hilt features, and comparing minute details to known and dated swords. In the case where there is a dealer name but no maker mark, you can date the item by looking up the dealer and when he was in business. They often change names so you have to look at the right name. There are books for this. Also, there are inspectors marks and reference books on when that certain inspector was performing inspections. It takes reference books and close study of the variations, markings, etc.

By the way for all sword collectors - John Thillmann's long awaited second book on swords is now being sold and I had the chance to look it over. A terrific book, must have reference! It is available through Man At Arms.