A crowd gathers Tuesday at the California state Capitol in Sacramento at a rally in support of abortion rights.

At the U.S. Supreme Court, statehouses and other sites across the nation, abortion rights supporters held rallies Tuesday in opposition to the wave of abortion bans being enacted this year in Midwestern and Southern states.

Organizers — including Planned Parenthood, NARAL Pro-Choice America and the American Civil Liberties Union — predicted tens of thousands of people would attend hundreds of events scheduled in all 50 states.

The “National Day of Action to Stop the Bans” came in response to a near-total ban on abortion recently signed into law in Alabama, as well as bills enacted or nearing passage in Mississippi, Kentucky, Ohio, Georgia and Louisiana aimed at banning abortion once a fetal heartbeat is detected. That can happen in the sixth week of pregnancy, before many women know they’re pregnant. Missouri lawmakers passed an eight-week ban.

None of the laws has taken effect, and all will likely be blocked while legal challenges play out. Ban supporters hope one or more of the measures might reach the Supreme Court and possibly trigger reversal of the 1973 Roe v. Wade decision that legalized abortion nationwide.

In Washington, a demonstration outside the Supreme Court drew hundreds of protesters and several Democratic presidential candidates. Sens. Cory Booker of New Jersey, Kirsten Gillibrand of New York, Bernie Sanders of Vermont and Amy Klobuchar of Minnesota, in addition to Reps. Eric Swalwell of California and Tim Ryan of Ohio, were among the attendees as multiple members of Congress spoke to a crowd that hoisted signs defending abortion rights.

Some protesters carried purple signs that declared, “Abortion is a human right.” Among their chants: “No church/No state/Women must decide their fate.”

In Atlanta, several hundred protesters jammed onto the steps of the Georgia statehouse.

Chants of “Vote them out!” and “My body, my right!” blared through a loudspeaker as passing drivers honked their horns in support.

In St. Louis, several hundred protesters gathered in a park between the Gateway Arch and the historic courthouse where the Dred Scott case decision that deemed black slaves as property, not citizens, was heard.

Katie Lorentz, a 19-year-old college student, said she worries that if she ever needs an abortion she’ll be criminalized.

“It puts a lot of women in danger,” Lorentz said of the new law. “States with strong anti-abortion laws have higher women mortality rates and infant mortality rates.”