Chadwick Boseman donated part of his own salary for this film to secure Sienna Miller as a co-star when the studio refused to match her salary demands.
Chadwick Boseman's last theatrically released film before his death on August 28, 2020.
The incoming phone number for the call at 44 minute is (212) 187-1013: 212 is the NY area code; 187 is the police code for murder in the State of CA (in NY, the murder code is 125); 10-13 is the code for "officer needs assistance."
The title "21 Bridges" refers to the 21 connections in and out of Manhattan island. Indeed 21 "bridges" exist, though only 17 of the connections are actually bridges: the remaining four connections are tunnels. The list of bridges includes: Brooklyn, Manhattan, Williamsburg, Queensboro, RFK, Willis Avenue, Third Avenue, Madison Avenue, 145th St, Macombs Dam, The High, Alexander Hamilton, Washington, University Heights, Broadway, Henry Hudson, and the George Washington. The four tunnels are Brooklyn-Battery, Holland, Lincoln, and the Queens-Midtown.
Originally titled "17 Bridges."