The building stands on the original site of the 1832 Ponce de León ranch.

Trost was the area's foremost pioneer in the use of reinforced concrete.

The building stands on a corner site opposite San Jacinto Plaza, with a gracefully curved street facade that wraps around the south and east sides.

Like many of Trost's designs, the Anson Mills Building's overall form and strong verticality, as well as details of the ornamentation and cornice, are reminiscent of the Chicago School work of Louis Sullivan.

In 1974, the Mills Building's windows were replaced with vertical bands of mirrored glass, radically altering its appearance.