What is on the Back of a Nickel?

By GovMint :

The back, or reverse, of the current Jefferson nickel features a depiction of Monticello, Thomas Jefferson's iconic Virginia estate. This design has been a staple since 1938, with a brief hiatus from 2004 to 2005 during the Westward Journey Nickel Series that celebrated the 200th anniversary of the Louisiana Purchase and the Lewis and Clark Expedition. Artist Felix Schlag created the Monticello design used from 1938 to 2003, beautifully capturing the neoclassical architecture of Jefferson's home. Starting in 2006, the "Return to Monticello" design began appearing on the nickel, which was a restored version of Schlag's original design.

The Jefferson Nickel was preceded by the Buffalo Nickel, which was minted from 1913 to 1938. Sculptor James Earle Fraser crafted the reverse of the Buffalo Nickel, which features a majestic American bison.

Sources Used:

https://www.usmint.gov/coins/coin-medal-programs/circulating-coins/return-to-monticello 

https://www.usmint.gov/coins/coin-medal-programs/circulating-coins/nickel