As one of the first parks in the city (established in 1815 as a public commons), Union Square has been the subject of many early photos.
This one below is from 1893. published in the wonderful book New York Then and Now, it looks west at the south end of Fourth Avenue and East 14th Street.
“This photo was probably taken on an early Sunday morning, for on 14th Street—a popular and important shopping center—stores are closed, there is little traffic, and only a few pedestrians are evident,” reads the caption.
At right is the equestrian statue of George Washington; farther back is one of Lafayette. On the southwest corner of Broadway and 14th Street is the Domestic Sewing Machine Building. On the northwest corner of 14th and University is the nine-story Lincoln Building, from 1885.
Here’s the same stretch in 1974, when Union Square was seedy and derelict. The statues have been moved inside the park; the Domestic Sewing Machine Building is gone. Mays, a discount department store, dominated the south side of Union Square.
Now, in 2012, Union Square is luxe again. We’ve got Whole Foods instead of Mays, which departed in the late 1980s. A glass condo rises on 14th and University Place. The one constant: the Lincoln Building, on the right, now housing a Diesel clothing store.