LOS ANGELES (CBSLA.com) — Fifty years ago this evening, the Beatles made history with their American television debut, live on “The Ed Sullivan Show.”

Casey Piotrowski, host of “The Beatles Show” (a weekly, one-hour radio show out of WPMD  at Cerritos College) has a new book ranking the Fab Four’s 50 most memorable moments.

READ MORE: Exclusive: Granada Hills Residents Fear For Their Safety, Property Values As Junk Piles In Neighbors Yard

He thinks the Sullivan appearance ranks #1.

“The Beatles preach that peace and love is their message, and I don’t think they’ve even realized it, but the real message is hope,” says Piotrowski about the group’s lasting impact.

CBS2’s Stephanie Simmons spoke to Piotrowski about his book and where several celebrated moments place for the music world’s best-selling band ever.

The author believes the Beatles got America through some of its most turbulent times — the Vietnam era, the civil rights struggle.

“We needed a lot of reassurance then, that things were gonna be okay through this social upheaval we were dealing with,” he tells Simmons.

He believes their music still resonates for much of the same reason.

“You look at what’s going on in the world now, terrorism, too much gun violence, weak economy. Maybe we need the Beatles music more now than we did 50 years ago,” he says.

READ MORE: Have You Noticed Higher Gas Prices Lately? You're Not Alone

In Piotrowski’s book, he discusses crucial moments in the band’s history — both good and bad.

At #49, the release of the movie “Yellow Submarine.”

#42, the release of John Lennon’s “Imagine,” his first studio album and an anthem for peace.

#35, Yoko Ono. “She was the lightning rod for the Beatles, obviously. She didn’t break the Beatles up, but she probably had a hand in it,” the author says.

#6, Ringo Starr joins the group.

#2, the release of “Sgt. Pepper’s Lonely Hearts Club Band.”

In Casey’s mind, the #1 is obvious.  The aforementioned Beatles on Sullivan.

MORE NEWS: Teachers, Food Workers Now Eligible To Get Vaccinated In LA County

“You’ll never have that kind of a moment again. Even today, that first Sullivan show appearance, if you were just the audience for current day population, it would still be the highest rated regular episode of a TV series in American television history,” Piotrowski says.