This street, via XX Settembre, is named after the date –September 20th- when the city of Rome was annexed to the Italian nation. It follows the line of a road first created by Pius IV and then incorporated into Pope Sixtus V's city plans at the end of the 16th century.

This Pope was called by the Roman poet Belli "Il Papa Tosto" the Brazen Pope, for his daring plans. The pope decided to develop the whole zone extending from the Baths of Diocletian to the Quirinale and the Pincio Hill. For this purpose, a good water supply was needed.
The pope's architect, Domenico Fontana, set about and reopened the ancient Alexandrine aqueduct, renaming it "Acqua Felice" in honor of the Pope's surname. With the same rapidity that distinguished all the public works undertaken during the pontificate of Sixtus V, Fontana completed this work in just 2 years.
The original design was to have the water of the Acqua Felice gush out onto a great triumphal arch. However, the fountain soon became known as the Fountain of Moses because of the huge statue of Moses made by Leonardo Sormani that was placed inside the central arch.
This Moses is very different from Michelangelo's statue made just a few years earlier. The Romans hated it and made it the object of criticism and derision.