Correct. Avatar was released in December 2009 and had very little competition (only Sherlock Holmes really) .
Avatar had serious legs and was #1 at the box office for quite some . It really did come out at the perfect time and highlighted the 3D craze which definitely helped out its box office big time .
Whats even more insane is that Avatar made about $700 million + over Infinity War .
Avatar 's box office totals
Domestic: $760,507,625 27.3%
+ Foreign: $2,027,457,462 72.7%
= Worldwide: $2,787,965,087
compared to Infinity War
Domestic: $678,815,482 33.1%
+ Foreign: $1,369,544,272 66.9%
= Worldwide: $2,048,359,754
I do think Endgame will most likely blow by Avatar domestically but worldwide might be another story.