If your site is already listed in a another portion of Living History, please do not resubmit it to By Time Period. Multi-listing within the same Topical area (i.e. Living History) is prohibited by the ODP Guidelines (see: Multiple Listings of an URL).
The "century" level subcategories utilize pointer links to the various periods housed in By Historical Region. Your submission has a better chance of being processed in that section.
Subcategories in this section of Living History are those that do not fit under other Living History subcategories. Typically sites found here belong in categories covering multiple continents, e.g. World War II.