Thanks to the Transformers franchise.
On Fourth of July Michael Bay became the second highest grossing film director in the United States with a lifetime domestic gross of $2.047 billion, $1.222 billion of which is from his "Transformers" films.
Robert Zemeckis who directed Back to the Future and Forrest Gump was previously the second highest grossing director in the United States, with a lifetime domestic gross of $2.038 billion.
Now Bay only needs to top Steven Spielberg's lifetime gross of 4.155 billion. I say "only" because Spielberg isn't directing any popular projects in the foreseeable future; meanwhile, Bay's Transformers: Age of Extinction lifetime gross is expected to double, and he could potentially direct Bad Boys 3 and Transformers 5 in the foreseeable future.
Sources:
- BoxOfficeMojo.com | PEOPLE INDEX - Directors | Retrieved July 5, 2014 at 2:16 PST