Opening of the Brooklyn Bridge
The Brooklyn Bridge, linking Manhattan and Brooklyn, opened — an early suspension bridge with steel cables and the longest suspension bridge in the world at the time.

Currier & Ives · Public domain · Source
Its designer John Roebling was injured while surveying and died in 1869; his son Washington Roebling, who took over, was struck down by caisson disease after working in the pressurised chambers under the riverbed. From then on his wife, Emily Warren Roebling, carried his instructions to the site and all but ran the work. After fourteen years the bridge opened on 24 May 1883, and Emily was the first to cross it.
With a span of 486 m between its two Gothic towers hung on steel cables, it was then the longest suspension bridge in the world. Six days after the opening a rumour that the bridge was collapsing caused a crush in which twelve people died; the next year, the story goes, a circus marched twenty-one elephants across to show how strong it was.