Julián Castro is pictured at his office in 2014. At the time, he was secretary for the Department of Housing and Urban Development.
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Castro and his brother pose with their grandmother, Victoria Castro, on the day they turned 12. She crossed into the United States at Eagle Pass, Texas, in 1922.
Castro announces in 2008 that he would be running for mayor of San Antonio. In 2001, he had become the youngest city councilman ever elected in San Antonio.
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Castro smiles at his campaign headquarters in 2009. He became mayor that year and won re-election in 2011 and 2013.
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Castro, center, is joined on stage with his wife, Erica, and their daughter, Carina, at an event in September 2012. Castro's brother, Joaquin, is at right.
Castro is interviewed by ABC's Diane Sawyer in September 2012. They were in Charlotte, North Carolina, for the Democratic National Convention.
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Castro, left, and his brother wave from the stage of the Democratic National Convention. Julian became the first Hispanic ever to deliver the convention's keynote address.
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"My family's story isn't special. What's special is the America that makes our story possible," Castro said in his convention speech. "Ours is a nation like no other -- a place where great journeys can be made in a single generation ... no matter who you are or where you come from, the path is always forward."
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First lady Michelle Obama speaks with Julian Castro, center, and Joaquin Castro at the Democratic National Convention.
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Julian Castro, right, is one minute older than his brother. Joaquin Castro has represented Texas' 20th congressional district since 2013.
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Erica and Julian Castro watch the San Antonio Spurs play in the NBA Finals in 2013.