But for many, Monday's holiday was a last chance to enjoy a final summer cookout, roller coaster ride or day at the beach. Or perhaps even a stroll from Michigan's Upper Peninsula to its Lower Peninsula — along the longest suspension bridge in the Western Hemisphere.
Politics was a big part of Labor Day, the time when much of the public usually starts to pay attention to the campaigns.
Terence Glaze, a 47-year-old firefighter, waited to catch a glimpse of Obama's motorcade at the president's speech in Toledo, but his two young sons were eager to get to the movies instead.
"It's a time for the family to be together and just spend time with one another. That's the most important aspect," Glaze said.
"But I do also think about the sacrifices unions have made, as it relates to wages, as it relates to safety issues," he added.
At his speech to members of the United Auto Workers and United Steelworkers, Obama noted his decision to rescue automakers General Motors and Chrysler in 2009 — a move opposed by his rival, Republican nominee Mitt Romney.
"If America had thrown in the towel like that, GM and Chrysler wouldn't exist today," Obama said. "The suppliers and the distributors that get their business from these companies would have died off, too. Then even Ford could have gone down as well."
Romney supporter Kenneth Harbin, a member of the University of Toledo College Republicans, waved signs for his candidate outside the rally and scoffed at Obama's decision to visit the labor stronghold.
"He's gotta come home and say, 'Here's what I did for you. Now here's what you can do for me,'" Harbin said.
Getting union voters in Ohio to turn out in November will be crucial for Democrats. About 650,000 workers in the state — or 13 percent — are union members. The national average is just less than 12 percent.
Union worker Mike Schreiner showed up for Toledo's annual Labor Day parade because he loves the bands, the school teams and the hot dogs.
"All the kids line up and we throw Frisbees and get the candy out to 'em. They won't even have to do any trick or treatin' this year — they got enough candy," said Schreiner, 57.
More than 300 people marched in the Charlotte, N.C., Labor Day Parade, an overwhelmingly pro-Obama event a day before Tuesday's kickoff of the Democratic National Convention.
North Carolina bans collective bargaining for teachers and other public workers and has the lowest percentage of union members in the U.S.
Gil Crittendon of the National Postal Mail Handlers Union Local 305 said he was marching in Charlotte because "it's important that we stick together and push back."
Republican vice presidential candidate Paul Ryan campaigned in Greenville, N.C., on Labor Day as part of an effort to counter the Democrats' message.
"People are not better off than they were four years ago. After another four years of this, who knows what it'll look like then?" Ryan said. "We're not going to let that happen."
In Buena Vista, Va., a small town on the western slopes of the Blue Ridge Mountains, marchers dodged downpours from the remnants of Hurricane Isaac in a traditional parade featuring vintage stock cars and both candidates in the U.S. Senate race.
Democrat Tim Kaine and Republican George Allen walked the 1½-mile route — separately.
In another hotly contested race, Massachusetts's Republican U.S. Sen. Scott Brown and Democratic challenger Elizabeth Warren both marched in Monday's Labor Day parade in Marlborough, west of Boston.
There was a 5-mile march in Michigan, led by Gov. Rick Snyder. He and thousands of people walked across the Mackinac Bridge linking the state's Upper and Lower peninsulas in a popular Labor Day tradition.
Snyder set a brisk 12-minute-per-mile pace in the walk, which runs from St. Ignace in the Upper Peninsula to Mackinaw City. Labor Day is the one time pedestrians can use the bridge across the Straits of Mackinac where Lakes Huron and Michigan converge.
"The walk was a blast because you're with thousands of Michiganders," Snyder said in a telephone interview after arriving in Mackinaw City.
Randall Ketchapaw, 33, of Wayland, has walked it every year since 1991 — 22 times — and is passing the tradition on to the next generation.
"My son here started when he was 3 months old," Ketchapaw said. "This is his sixth walk. Sixth stroll, I should say."
Along the streets of New York City's borough of Brooklyn, people waved flags from their front stoops, drumbeats filled the air and women in brightly colored sequined costumes and feather headdresses danced to reggae music in the West Indian Day Parade.
The festive climate prevailed a year after violence marred the annual celebration of the culture of the Caribbean islands. In 2011, a bystander was killed by a stray bullet hours after the parade when police fired on an armed suspect.
About 20 Occupy Wall Street protesters were told they had to leave the parade in the middle of the route because they did not have a permit. They ended up briefly standing off to the side of the street surrounded by police.
Several hundred people lined streets in Buffalo, N.Y., to cheer members of about 50 unions as well as Irish step dancers, a high school marching band and Santa Claus and Abe Lincoln impersonators.
Candidates for local and state offices sweltered in 85-degree sunshine as they brought up the rear, shaking hands and handing out campaign literature.
Walter Lukasziwicz, 79, wearing a UAW baseball cap and T-shirt, said he came to watch the parade and show support for the union-won wages and benefits he received during 37 years at Ford and since retiring from the plant in the Buffalo suburb of Hamburg.
"Unions protect the workers," he said.
About 100 Teamsters and supporters wore matching red T-shirts saying "Stop the war on workers" and held signs with the same message.
"More get involved every year. Working people are suffering more than ever," said George Harrigan of the Teamsters Joint Council No. 46. He said the show of unity was important "so that people can see labor is out in force to protect their rights."
Marchers with the United University Professions carried signs reading, "Kids, not cuts!" and "Proud lobbyists for students."
Earlier Monday, nearly 600 runners took part in the Labor Day Fleet Feet run through downtown Buffalo. The race raises money for Shoes on Students, which provides training shoes to high school students in need.
In other Labor Day events:
— Hundreds of unionized janitors from eastern Massachusetts rallied on Boston Common for more work, calling it crucial to building the middle class. The march came as the janitors' contract is set to expire at the end of the month.
— In Rhode Island's capital, about 200 union members, students and Occupy Providence members marched from Brown University to the city's financial district, arguing that educational and financial institutions must help fix the economy and rebuild the middle class.
— Thousands of union workers packed Chicago's Daley Plaza to show support for the city's teachers in contract talks with the school district, one day before the start of classes for most public school students and a week before a threatened strike.