Factual error: Mark Felt is driving by the Lincoln Memorial in the background, with the WWII Memorial in the foreground. The WWII Memorial was begun in 2001 and completed in 2004, way after the movie's timeframe. (01:26:21)
Factual error: When Mark Felts initially pulls up to the FBI building he parks in the Deputy Associate Director's parking spot. He was not named to that position until after Hoover died and the current Deputy Associate Director who had that position since 1930, Clyde Tolson, resigned.