Authorities said everything had stayed peaceful for the most part, but three people were arrested on suspicion of smashing vehicle windows.
Other marches against the Islamic law have drawn larger counter-rallies in some USA cities.
Demonstrators dispersed after about two hours, with police escorting Trump loyalists across the river while counter protesters chanted "hey hey, goodbye".
Meanwhile, others made their way toward Occidental Park in Pioneer Square, where police used pepper spray and made several arrests.
In front of the Trump building in downtown Chicago, about 30 people demonstrated against Islamic law and in favor of President Donald Trump, shouting slogans and holding signs that read "Ban Sharia" and "Sharia abuses women".
"This is a march against Sharia law and for human rights", according to a statement posted on Act for America's website.
"They claim to be anti this small portion of the Muslim population supposedly but they are a anti Muslim group", said Marie.
Protesters scuffle at the state capitol in St. Paul, Minnesota.More news: Sea of Thieves Gets New Footage, To Launch In Early 2018
A confrontation that included shoving and punching occurred, The Star Tribune reported. Counter-protesters gathered as well.
Colorado State Troopers and Denver Police put up yellow tape around the capitol steps to keep the two sides well away from each other. The Minnesota State Patrol arrested about a half-dozen people.
Demonstrators gathered to protest against Islamic law take part in a rally Saturday, June 10, 2017, in NY. Members of ACT for America yelled "No Sharia in America" while the counter protestors yelled "Say it loud, say it clear Muslims are welcome here".
"I firmly believe that whenever you see or hear Nazis or the KKK, you should come out and protest against them", she said.
More than 100 organizations sent letters to the mayors of the 29 cities where marches are planned. In more than 20 cities, they were met by pro-Muslim demonstrations. "Make America great." Griffin, of Orlando, held a sign reading, "My Muslim students make America great". In New York, for example, the "anti-Shariah" rally involved around three dozen people, while counter-protesters numbered in the hundreds. Local activists set up an "Ask an American Muslim" booth where attendees could meet and learn about their Muslim neighbors.
Participants anxious that Islamic law could influence US courts and harm women, among other concerns.
In Harrisburg, Pennsylvania, more than a dozen men belonging to the anti-government Oath Keepers were on hand, invited by ACT to provide security.
Its highly effective grassroots campaign has resulted in more than 13 states introducing bills to ban Shariah law even though there would be clear constitutional constraints to somehow making religious law supersede US law.