The film earned $659.3 million as of Friday, coming in just shy of Titanic's $659.5 million, which it easily surpassed the following day.
Titanic has sunk to the fourth spot to make way for Black Panther on the list of third-highest grossing USA theatrical releases.
Black Panther was written and directed by a black man and the cast is nearly entirely black, save for the charmingly out-of-place hobbits Martin Freeman and Andy Serkis.
"Titanic" brought in $659.5 million domestic total with "The Force Awakens" bringing in $936 million and Avatar bringing in $760 million.
The film, which was directed by Ryan Coogler, stands at $1.29 billion worldwide, ahead of smashes such as Frozen, and 2017 mega-hits Beauty and the Beast and The Fate of the Furious.
The success of Marvel's Black Panther, both critically and financially, continues to grow, with the movie's latest milestone falling into the latter category.
It's yet another honor for "Black Panther", which has already broken several box-office records and reached $1 billion globally since coming to theaters last month.
"Titanic", starring Leonardo DiCaprio and Kate Winslet, held a spot in the top three for two decades.