America: A Tribute to Heroes aired Friday night on more than 30 networks, including ABC, CBS, NBC, FOX, UPN and the WB and was seen in about 210 countries.
According to Nielsen Media Research, the 59.3 million viewers who tuned in to the commercial-free two-hour broadcast compares to the 80 million who watched the Super Bowl or news coverage on the night of the attacks.
Nielsen also estimated that about 89 million people watched at least part of the telethon.
Organizers will not know how much money was raised until Monday. Sources say that around 300,000 calls were logged in the first 15 minutes of the telecast.
A long list of stars made appearances at the telethon. Musical acts included Bruce Springsteen, Billy Joel, Paul Simon, Mariah Carey, U2, Stevie Wonder, Neil Young, Limp Bizkit, Sheryl Crow and Tom Petty.
Roberts, who lives in New York, also donated $1 million to the telethon, in addition to the $1 million she donated to the American Red Cross Disaster Relief Fund.