And they cheered again last night as the Olympic champion strolled onto the stage at historic Fort McHenry, celebrating as they watched each of his wins.
It was as if, after six weeks on the celebrity circuit, he was used to being treated like a fourth Jonas brother or a cast member of MTV's The Hills.
Phelps finally came home to celebrate his transcendence yesterday, riding in the parade through his former stomping grounds of Towson and appearing last night at a Star Spangled Salute concert and fireworks show at Fort McHenry. He had talked, ever since winning his record eighth gold medal, about his eagerness to return.
Yesterday, the Baltimore area got to show how eager it was to have him.
Parade organizers estimated that between 30,000 and 40,000 people showed up in Towson to greet Phelps, fellow Olympic medalist Katie Hoff, Paralympic champion Jessica Long and several other Olympians. And 10,000 or more were estimated to have attended the Fort McHenry event.
"Everyone here is so supportive of everybody, especially sports," Phelps said last night at a news conference following the day of celebration. He noted how many high school friends and former teachers he saw along the parade route.
"It was cool. I literally tried to pick out who I knew and who I didn't."
Sure, there were the politicians and fire engines and marching bands common to all parades.
But it was the chance to glimpse Phelps that drew everyone from aged nuns to bouncing toddlers to fiery political protesters to the side of York Road. They donned red, white and blue beads and waved "Phelps Phans" signs.
Many set up lawn chairs and blankets before noon so they'd be assured of a glimpse when he rolled by hours later.
When asked why they set aside a Saturday afternoon to watch the parade, onlookers gave quizzical looks and said, "Well, Michael Phelps."
"Why wouldn't you want to be within 10 feet of such greatness?" they seemed to mean.
"He makes Maryland stand out," said Sharon Seidman of Columbia, who wore a Phelps T-shirt and snapped photos as he passed.
"With all the negative stuff going on in the world, the economy and all, this is America," said her husband, Jerry. "Everybody showing up to support our hometown Olympian."
Fans at Fort McHenry effused, as well, as they enjoyed performances by the Morgan State University choir and U.S. Naval Academy Concert Band, and the fireworks.
As Phelps' eight gold medal swims were displayed on a giant screen, the applause grew louder and louder, reaching its peak when Access Hollywood host Billy Bush, serving as the master of ceremonies, urged the crowd to "say hello the greatest Olympic champion of all time, Michael Phelps."
"I wanted to give my children a chance to see a Maryland Olympian up close," said Elaine Liberto of Catonsville, whose children swim competitively.