The cache is not at the posted coordinates.
In order to find this cache, you'll need to complete the nearby Adventure Lab - National Infantry Museum Outdoor Walking Tour - Part 2.
Once you complete the Adventure Lab, you will have to scroll through the Journal to the last entry to see the Final Coordinates.
Use the Parking Reference point to get into the parking lot.
Congratulations to Mrs. Captain Picard and Footnotes coach for their FTF on both this cache and the National Infantry Museum Walking Tour - Part 2 Adventure Lab!