David Muir, Diane Sawyer and Deborah Roberts talk to USA TODAY about ABC's 24-hour live broadcast for America 250 and the power of journalism today.

David Muir, Diane Sawyer and Deborah Roberts talk to USA TODAY about ABC's 24-hour live broadcast for America 250 and the power of journalism today.

From a light show and Brandi Carlile performance at the Statue of Liberty to a July 4 bash in Nashville, and visits to all 50 states and the seven natural wonders of America in…