His book includes a photo of some of the 200 volunteers from St. Charles Borromeo Seminary digging graves. "Those men were heroic," Williams said.
So were thousands of women, he said, who replaced men in factories, manufacturing everything from steel doughboy helmets at the Edward G. Budd Co. to bullets at the Frankford Arsenal.
Williams wrote to the mayors of two French towns, Villequier-Aumont and Frieres-Faillouel, where women from Emergency Aid of Pennsylvania in Philadelphia had been distributing food and medical supplies when the Germans attacked.
"Those women helped evacuate both towns while under German artillery bombardment," Williams said. "Their courage is not known here today."
After sending the letters, he said: "I got a phone call from the mayor of Villequier-Aumont, who heard his grandfather's stories about the courage of those women. He said both towns renamed the main thoroughfares 'Rue de Philadelphia' in their honor."
Williams is as South Philly as his Mummer roots.
"My grandfather got me into a Comic club for the 1957 parade, when I was 18 months old, dressed in a clown suit, carrying an umbrella," Williams said.
He remembered a 1970s visit from his grandfather's friend, John Fralinger Jr., who asked if young Williams played an instrument.
"I play clarinet," Williams told Fralinger, who said, "Get this kid a saxophone."
Williams has marched with his sax in string bands ever since, first with Fralinger's, then Avalon, now Pennsport.
"We're an outlaw band," Williams said, laughing. "We're guys who marched with other bands, retired, wanted to get back into it but not all year long. We rehearse a few months for the parade."
To this day, Williams said, "There's no thrill like marching on Broad Street and you're coming around the corner and the big lights hit you in front of the judges and you have four minutes to put on a show.
"There's nothing like the adrenaline rush of 'Here we go!' "
Williams will talk about his book and sign copies at 5 p.m. Dec. 20 at Barnes & Noble, 2300 Chemical Road, Plymouth Meeting.
On Twitter: @DanGeringer