A quote in Bryan Burwell's column Oct. 7 attributed to Rush Limbaugh about the merits of slavery in the United States cannot be verified, and its use did not meet the Post-Dispatch's standards for sourcing.

Limbaugh said he did not make the statement.

Burwell's column did not identify the source of the quote, which was Jack Huberman's 2006 book "101 People Who Are Really Screwing America." The book provided no details about the origin of the quote. When contacted by the Post-Dispatch, Huberman said that he had a source for the quote but declined to reveal it on advice of counsel. The book's publisher, Nation Books, did not return calls to the Post-Dispatch.

The Post-Dispatch found references attributing the quote to Limbaugh in other publications and on Internet blogs as far back as 1993, but none of those cited a source.