Hell Gate Bridge is a railroad bridge. It is the place where waters from Long Island Sound meet the waters of the East River. A fleet of 100 smuggling boats and ships, operated by the Dwyer/Costello Liquor Syndicate, was located at 132 and Locust, near the bridge, during Prohibition.
At sunset (hence called the “Sunset Fleet”), these vessels would move down the East River, through the bay, into the Narrows and out into the Atlantic Ocean. They would search out liquor supply boats, often “foreign” ships, on Rum Row some twelve or more miles out.
The photo above of Hell Gate Bridge (the arched one in back) was taken from the park in front of Gracie Mansion looking northeast. This is the same view smugglers would have encountered on returning to the marina except they usually traveled the return trip from Rum Row in the dark.
(Mayor LaGuardia did not move into Gracie Mansion in 1942 after it became the official residence for the city’s mayors but sometimes came there to sit on the porch on hot summer evenings to watch the river traffic.)
[ For more, on LaGuardia and Prohibition, including selections from speeches against it, see Smugglers, Bootleggers, and Scofflaws: Prohibition and New York City (SUNY Press 2013). The book, less than 200 pages, is a scholarly one and includes text, photographs, footnotes, bibliography, index, and selected primary documents.]