What was it called when it opened?
Answer:
Originally referred to as the New York and Brooklyn Bridge and as the East River Bridge, it was dubbed the Brooklyn Bridge in a January 25, 1867 letter to the editor of the Brooklyn Daily Eagle,and formally so named by the city government in 1915.
As a weird piece of trivia, one week after the opening of the not-yet-called Brooklyn Bridge (May 30, 1883), a rumor that it was going to collapse caused a stampede, which crushed and killed at least twelve people.