Between 1928 and 1945, the Loggia became the venue for clandestine meetings of the Catholic Scouting Association Aquile Randagie (Stray Eagles), which was banned by the fascist regime. Every Sunday the scouts would be there, where they celebrated mass and then left for their outings. From the days following 25 April 1945, a spontaneous memorial was formed here, where residents of Milan displayed photographs of their dead.

On 1 June 1952, Giulia Leoni Voghera and her daughter Augusta, two Jewish women who were barbarically murdered in the Bolzano concentration camp, were commemorated under the Loggia. That same year, on 11 October, Sergio Papi, Luigi Fossati and Ugo Cellini, three soldiers tried as deserters and shot on 19 October 1944 in the Münsingen training camp in Germany, were also commemorated here.

The following year, the Comitato Onoranze Caduti per la Libertà (Committee for Honouring the Fallen for Freedom Victims), which grouped together the main associations arising from the Resistance and was chaired by Liberation Mayor, Antonio Greppi, commissioned the Committee's secretary, Marcella Chiorri Principato, to draw up the official list for the Loggia. The list included 1,739 names, including partisans, political deportees, workers arrested for taking part in the March 1944 strikes, and Milanese Jews taken to Nazi concentration camps as a result of anti-Semitic persecution. The 19 bronze slabs were inaugurated on the 8th anniversary of the Liberation, 25 April 1953, with a solemn ceremony at which Mayor Greppi and resistance leader, Ferruccio Parri, both spoke.

For over forty years, the Milan provincial ANPI has been fighting for the development of the Loggia dei Mercanti, which is the city's main Resistance monument. This is recalled by Giovanni Pesce in 1963 in the City Council, and by Tino Casali in a letter to Mayor Tognoli in 1984.

In 2013, a new subscription was opened for the redevelopment of the area, which saw the placement of a Totem with a quotation by Piero Calamandrei. In 2021, the new square was inaugurated, curated by Cini and Antonio Boeri and donated by the ANPI to the city.