Forbes wrote a piece about this hearing: How Emotional Intelligence Landed Mr. Rogers $20 Million
On the 1st of May in 1969, Mr. Rogers addressed the Senate to argue that $20 million in funding for PBS should not be cut. John Pastore, the Senator from Rhode Island who led the hearing, had never seen nor hear of Mr. Rogers’ television show. It took Mr. Rogers just six minutes to convince the gruff and impatient Senator from Rhode Island that the $20 million was well worth it.
This video about 35 Facts about Mr. Rogers is great too, especially the anecdote about the limo driver.