The American bison was in danger of extinction since the 19th century but has had a recent resurgence.
The American bison was in danger for extinction since the 19th century but has had a recent resurgence.
The American bison was in danger of extinction since the 19th century but has had a recent resurgence.
The American bison was in danger for extinction since the 19th century but has had a recent resurgence.
The phrase "in danger of" is idiomatically correct. Any other preposition in the place of "of" is incorrect.