It's a small version of the stars and stripes, tiny enough to slide into his sock, and big enough to send a message to anyone who watched the Cubs-Astros game on Sept. 27, 2001, that America was alive and well and still had spirit after the events of 9/11. That flag is linked to Sammy Sosa, who used it to show how much he loved the U.S.A., and how badly he felt about the tragedy.
Williams was the Cubs' first-base coach for that game, the team's first at Wrigley Field after the Sept. 11, 2001, terrorist attacks. Chicago beat Cincinnati, 8-2, on Sept. 10 at Wrigley Field, and Game 2 of that series was to be played the next day. But regular-season games were postponed, and the Cubs did not return to action until Sept. 18, on the road in Cincinnati.
They came home for a three-game series against the Astros, and Sosa felt he needed to do something. As he ran out to right field at the start of the game, he carried a small American flag with him. The sight of Sosa and the flag brought the crowd to its feet -- even before the first pitch.
"They were very excited -- me running out there with the flag in my hand, it was very exciting," Sosa said in an interview from his home in Miami. "It was an emotional moment. I wanted to do something, I wanted to pay tribute to the people hurt in 9/11. That's how I could show respect."
But Sosa wasn't done. He was going to hit a home run that night and told Williams, a Hall of Fame outfielder who is now a senior advisor to the team, to tuck a flag into his sock.
"I was in the game and I had a feeling, 'If I hit a home run today, how can I contribute to 9/11?'" Sosa said. "I spoke to Billy Williams. I said, 'If I hit a home run, make sure you have the flag and give it to me.' Everything went according to plan."
It was 57 degrees at game time and the wind was blowing in from the east that night at seven miles per hour, which is not conducive to home runs being hit at Wrigley Field. Eric Young and Rickey Gutierrez both grounded out to start the Cubs' first against Houston's Shane Reynolds. Sosa was ahead, 3-0, in the count when he connected, lofting the ball to right-center field for his 59th homer.
This wasn't one of Sosa's usual mammoth shots that cleared the left-field bleachers. This time, it was a line drive, and Williams wasn't sure it was going out.
"I had [the flag] in my sock," Williams said. "Sammy hit it, and I'm looking at the ball and Sammy was getting closer and closer and I see the ball and I said, 'Is this ball going to go? Is it going to go out of the ballpark or what?' All of a sudden, it's out of the ballpark -- boom. I had to get the flag out of my pants as quick as possible and give it to him.
"We had it all planned," Williams said. "The only thing was he had to hit a home run that night."
He finished with 609 homers in his career, and Sosa admits you can't plan them.
"I agree," Sosa said, "but I said, 'Billy, if it happens, [be ready].' It's one of those days when something feels like it's going your way, it happens. Everything went so well, I was shocked. I remember the wind was blowing in. It barely went out and like, 'wow.'"
Sosa grabbed the flag from Williams -- almost like a relay racer takes the baton -- and held it aloft as he trotted around the bases. The crowd of 38,154 went wild.
Don Baylor, then the Cubs' manager, didn't know about Sosa's plans until after it happened.
"It was pretty awesome," Baylor said. "America was together at that time and it was pretty special. For a Dominican-born player to be a part of that, I thought was pretty neat."
"I'm always happy that I could come to this country and get the opportunity to be who I am," Sosa said. "I always appreciate what America did for my family. I never forget who took care of me in the tough moments I went through in my career.
"This is the land of dreams," he said. "The hope and accomplishments you can make here is incredible. America will always, for me, be No. 1."
The Astros won the game, 6-5, but it's a moment in Cubs history that will shine. What if Sosa didn't connect that night?
"[The flag] wouldn't come out," Williams said. "That year, everything worked in Sammy's favor. The chances are, he was going to hit a home run that night. Boom, there she goes and everything worked out fine."
What if it was a double?
"No, he would've been running too fast," Williams said. "It had to be a home run or nothing. Everything was in his favor."
Sosa finished with 64 home runs that year, his third 60 homer season, and he led the National League with 160 RBIs, 146 runs and 425 total bases.
It's hard to believe it's been 10 years since 9/11.
"Time flies, doesn't it?" Williams said.
"It's true -- it seems like a long time ago," said Sosa, who now lives in Miami and the Dominican Republic, running a few businesses and preparing for the birth of his fifth child in December with wife Sonia. Their eldest daughter, Keysha, is 13.
And the small American flag?
"I had him sign it for me," Williams said, "and I still have it at home."