The Sentinel is a prestigious military academy based on The Citadel in Charleston, South Carolina that was founded in 1842.
The academy was shown in Chapter 8.
- The academy had a group of students known as the Riflemen Singers of which Frank Underwood was a member.
- The Sentinel is likely based on The Citadel a military college based in South Carolina. A library is constructed to replace an older building and it is named after Frank Underwood . The old library is extensively shown in Chapter 8.
- Frank Underwood mentioned that he was not an outstanding student, the President of the academy only contacted him to secure the donation for the library.
- The library is paid for by Sancorp, a natural gas company which promotes drilling in Washington.
- Frank Underwood has served on the Sentinel's Board of Visitors since 1994