In the 1960s, at the height of his career, he created his magnum opus Los Niños Héroes, depicting the sacrifice of six child soldiers during the Mexican-American War.

At 25 years of age, he returned to his native land of Jalisco and abandoned his brief teaching duties to focus his career as a muralist.

The city council also declared Gabriel Flores a "favorite son" and included his name in the School of Painters near Agua Azul park.

[5] There was a change in subject matter for Flores' murals at the turn of the 1970s, shifting from historical and universal themes to works containing his own ideas and feelings on social and political events.

He painted a series of murals, including Culto al Dinero (Worship of Money) and Estampas de la vida (Prints of Life), which did not garner much praise and were removed from exhibitions.