One of America’s wealthiest men, Dallas billionaire and philanthropist Harold Simmons, died Saturday night at the age of 82.

Harold Simmons’ wife, Annette, told The Dallas Morning News her husband died at Baylor University Medical Center. Annette Simmons said her husband had been in Baylor’s intensive care unit for the last eight days, the newspaper reported. She did not give the cause of death.

The billionaire made his fortune through investing and corporate takeovers. The Dallas Morning News said his net worth was $10 billion. Two years ago, Harold Simmons gave millions of dollars to the Republican Party in an effort to defeat President Barack Obama’s re-election campaign.

In 2008, Harold Simmons bankrolled ads linking then-presidential candidate Barack Obama to William Ayers, a Vietnam-era militant who helped found the violent Weather Underground. Simmons was also a key backer of the Swift Boat Veterans’ attacks on Democratic presidential candidate John Kerry in 2004.

Billionaire Harold Simmons made his fortune through investing and corporate takeovers

He also gave money to Planned Parenthood and his foundation most recently donated $600,000 to the Resource Center of Dallas, which serves the gay, lesbian, bisexual and transgender community in Dallas.

Harold Simmons has given tens of millions of dollars to Republican candidates, including Texas Gov. Rick Perry and former presidential candidate Mitt Romney.

Rick Perry issued the following statement Sunday afternoon: “Harold Simmons was a true Texas giant, rising from humble beginnings and seizing the limitless opportunity for success we so deeply cherish in our great state. His legacy of hard work and giving, particularly to his beloved University of Texas, will live on for generations. Anita and I send our thoughts and prayers to the Simmons family.”

The arts community is also mourning the passing of Harold Simmons. He and his wife Annette donated $5 million to build the AT&T Performing Arts Center. The center issued this statement Sunday evening: “Dallas has lost a truly generous giant,” said Doug Curtis.

“The Simmons’ generosity has touched so many parts of our city. The Center considers itself fortunate to have the Simmons’ name gracing such a prominent part of our beautiful opera house. Our thoughts and prayers go out to the Simmons family.”

Harold Simmons, born to two school teachers in East Texas, became one of the richest men in the country with interests ranging from energy to chemicals. His spokesman Chuck McDonald said Harold Simmons died Saturday in Dallas. Chuck McDonald said he did not know the cause of death.

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