The 73nd annual East Los Angeles Mexican Independence Day Parade & Festival, billed by organizers as the longest running and largest of its kind in the United States, stepped off under clear skies Sunday.

The parade began at 10 a.m. at Cesar Chavez Avenue at Mednik Avenue and continued west along Cesar Chavez Avenue to Record Avenue.

It comes eight days before Mexican Independence Day and the start of Hispanic Heritage Month.

The parade's theme is "Encounter of Two Worlds," in celebration of the International Year of Indigenous Languages, proclaimed by the United Nations to raise awareness of and benefit people who speak Indigenous Languages and for others to appreciate the contribution they make to the world's cultural diversity.

The parade's grand marshal was world heavyweight boxing champion Andy Ruiz Jr., the first person of Mexican heritage to hold the title.

Elected officials who appeared in the parade included Los Angeles Mayor Eric Garcetti, Los Angeles County Sheriff Alex Villanueva, Los Angeles County Supervisor Hilda Solis, Rep. Lucille Roybal-Allard, D-Los Angeles, and Los Angeles Councilman Gil Cedillo.

"It's something I'm so proud of, this tradition of Los Angeles -- our roots on both sides of the border," Garcetti said. "I'm a Mexican-American whose grandfather was a dreamer, who came over the border in his mother's arms."

Also set to appear in the parade were Latin Grammy-winning Regional Mexican group Los Horoscopos de Durango; Sebastian Rulli and Renata Notni, stars of the Univision drama "El Dragon"; the doll muralist known as Sand One; and the artist Ofelia Esparza.

A festival follows the parade from 11 a.m.-5 p.m. on Mednik Avenue between Cesar Chavez Avenue and First Street with musical performances and other entertainment, attractions, food vendors, merchandise and interactive displays.