From the record
“Fort Duffield is a Union American Civil War fort located outside West Point, Kentucky. It saw use in 1862, and was abandoned when it appeared that the war would never come near the fort.”
Wikipedia article Fort Duffield, CC BY-SA 4.0.
One of 89 National Register listings published here for Hardin County · listed in 1994 · category: Site.
Sources: the Wikipedia article · the case file at the National Archives · the National Register database, National Park Service