On Friday, Seattle Mayor Ed Murray lauded the police department for wrangling the protesters.
"Seattle police officers conducted themselves with admirable patience and professionalism during May Day yesterday and throughout the night," Murray said. "Their training and preparation showed: Officers kept order in our streets and supported the marchers in their peaceful expression of their First Amendment rights. Arrests were limited in number, and damage to property was kept to a minimum."
Protesters chanted against police brutality, among other causes.
Violence has plagued May Day in Seattle during the past two years, with protesters challenging police in the streets and sometimes stealing the thunder of much larger daytime events calling for immigrant and worker rights. Last year, police arrested 18 people from a crowd that pelted them with rocks and bottles. Storefronts in downtown Seattle have also been smashed in previous protests.
On Thursday, Seattle police were out in force on bicycles, foot and horseback, supplementing their numbers with officers from several other jurisdictions. Protesters started trash can fires in the Capitol Hill neighborhood. One arrest came after a brick was hurled at police.
The anti-capitalist protesters had no permit, but police accompanied them as they marched in a rambling circuit from Capitol Hill to downtown Seattle and back again before officers hemmed them in. Some tossed firecrackers at police, officers said.
Seattle police noted a marked uptick in anti-authority rhetoric leading up to this year's May Day events, said Capt. Chris Fowler, in charge of the department's response to the demonstrations.
Businesses downtown prepared, posting security guards outside, taping paper over their windows to discourage graffiti, and using metal coat hangers to tie down iron grates along the sidewalks.
The earlier May Day rally started in south Seattle and headed to Westlake Park downtown, with demonstrators waving red signs seeking an end to deportations and "poverty wages" and calling for a $15-an-hour minimum wage.
Fowler told The Seattle Times that planners had expected nearly 700 people for the afternoon May Day march. He estimated the crowd size at closer to 400.
Earlier Thursday, Mayor Ed Murray announced a plan to phase in a $15 minimum wage in the city over the next seven years.
Daniel Stender, 26, was at the rally holding a sign pushing for quicker action on getting to a $15 minimum wage.
"It's getting ridiculous. It's getting to the point where you can't afford things," he said.
The police department's blog said vandals spray-painted a few businesses early Thursday in the Capitol Hill neighborhood - a car dealership, bank, restaurant and a post office.