Final answer:
Four of the 75 highest-grossing films of all time, according to Box Office Mojo, were released before 2000: Titanic, Star Wars: Episode IV - A New Hope, Jurassic Park, and Forrest Gump.
Step-by-step explanation:
Of the highest grossing films worldwide of all time, according to Box Office Mojo, four were released before 2000. The names of these movies are:
Titanic (1997) - directed by James Cameron
Star Wars: Episode IV - A New Hope (1977) - directed by George Lucas
Jurassic Park (1993) - directed by Steven Spielberg
Forrest Gump (1994) - directed by Robert Zemeckis