With its distinctive black, white, and green geometric pavement, it is a prominent urban oasis and gathering spot in Downtown Pittsburgh.

After World War II, the Aluminum Company of America (ALCOA), which was established in Pittsburgh in the 19th century, proposed to move to New York City.

A historical marker in the square commemorates the Founding Convention of the American Federation of Labor, which took place on November 15, 1881, in Turner Hall, near this location.

The Square serves as the backdrop to revealing scenes in the 2002 thriller The Mothman Prophecies with Richard Gere and Laura Linney.

Many Pittsburgh landmark buildings and cathedrals are showcased and get close-ups to add a visual layer to the revelations discussed in the square.