In 1930 Augustinčić created his first equestrian sculpture for the monument in Niš, after his design won the competition out of the 23 works submitted, with prominent Yugoslav sculptors Risto Stijović and Sreten Stojanović coming in second and third. From then on equestrian statues became one the hallmarks of his career, notable examples being the monument to Józef Piłsudski in Katowice, Poland (commissioned in the 1930s but placed in 1991) and his most notable work, the "Peace" monument, erected in front of the United Nations building in New York in 1954. In the late 1930s he also created a couple of monuments to King Alexander in Sombor and Skopje (which were later destroyed in World War II), as well as several sculptures of Croatian politician Stjepan Radić. Other notable works from this period include a number of family tomb headstones at the Mirogoj Cemetery in Zagreb, including "Sorrow" (1930), "Moses" (1932) and "Icarus" (1935).