- Refers to the context of or associated specifically with the modern political entity of the United States of America.
- Structures spanning and providing passage over waterways, topographic depressions, transportation routes, or similar circulation barriers.
- Prints made from an etched printing plate, which is a metal plate on which a design is made by coating the plate with an acid-resistant substance, creating a design in the coating, and then exposing the plate to acid, which etches the plate where the metal is exposed. For designs incised directly into a copper plate using a burin or graver, use "engravings (prints)."
- Refers to a building or group of buildings with the function of housing the action or process of making goods or producing anything, whether before or after the Industrial Revolution of the mid-19th century.