Presidents are not required by law to release their tax returns, but each has done so voluntarily since the early '70s.
An estimated 74 percent of Americans - as well as 60 percent of Republicans -want Trump to come clean on his taxes, which shows this is a nonpartisan issue, Smith said.
The "small rallies" were held at "dozens" of cities across the country, ranging from hundreds in South Florida at Trump's Mar-a-Lago resort, to thousands in the streets of New York City, per The Washington Post.
The rally ended with protesters walking around Central Square's perimeter chanting demands that Trump make his tax returns public.
Tuesday is the deadline for taxpayers to file returns.
While demonstrations across the country focused on the president's tax returns, participants said this rally and march is part of a 40 year tradition for the Peace and Justice Action League of Spokane.
Trump has previously said Americans don't care about his returns.
Seventy-one-year-old Ilene Singh said he's wrong.
Drug Maker Moves to Drop its own Lawsuit Halting Executions
She said the prisoners were entitled to challenge the execution method on grounds it "creates a demonstrated risk of severe pain". After that, officials say finding a supplier willing to allow the drug to be used to kill someone will be exceptionally hard .
A day after the massive January 21 women's march in Washington and other cities, comedy writer Frank Lesser tapped out on Twitter, "Trump claims no one cares about his taxes".
The arrests took place on Saturday in Berkeley, California, when fistfights broke out between supporters and opponents of the President, Efe news reported.
It was seen by some as the unofficial mascot for the protest - to suggest that the Republican president was afraid, or chicken, to publish his records. Officers confiscated knives, flagpoles, helmets and sticks with signs on them, things that were being used as weapons.
"We are taking the gloves off to say knock off the secrecy Mr President", said Senator Ron Wyden of OR, the ranking Democrat on the Senate Finance Committee.
"If he thinks he can get away with playing king, he's got another thought coming", Waters said.
Meanwhile, Democratic US Senator Elizabeth Warren, of MA, posted an online video on Friday urging Congress to force Trump to release the returns. Trump's break with precedent has raised questions about possible conflicts of interest.
"The only way we can know what kind of business ties our president has with businesses all over the world is by looking at his tax returns".
"He's the first presidential candidate to hesitate to release his taxes, and because of his many financial dealings in all these different countries, it's not clear how he's benefiting from deals he's made", Morton said.