Stamford, Conn. (NBC NEWS)- Conservative commentator and columnist William F. Buckley has died.

Buckley was found dead at his home in Stamford, Connecticut, Wednesday by his assistant. The cause of death isn't immediately known, but the assistant says Buckley had been ill with emphysema.

"He had a great way of defining the issues, it was erudite and yet a lot of folks from different walks of life could understand it. And he's a big figure in our history and he'll be missed and we ask for God's blessings on his soul," President Bush said Wednesday.

Buckley launched his conservative magazine "The National Review" in 1955, and gave up control of it in 2004. His TV show "Firing Line" enjoyed a 33-year run, until 1999. Buckley was 82.

Buckley was born in New York City in 1925,  the sixth of ten children of a multi-millionaire oil tycoon. Buckley's wife Pat died in April 2007.