For more than 25 hours starting March 31, 2025, and running into the next day, U.S. Sen. Cory Booker, D-N.J., gave a marathon speech on the Senate floor, expressing resistance to President Donald Trump. According to many posts about the occasion, Booker was performing a filibuster, breaking the record set by Sen. Strom Thurmond's filibuster of the 1957 Civil Rights Act.  

One post on X stated:

Booker has now broken the record as the longest single-person filibuster speech in the United States Senate.

The previous record was held by Strom Thurmond, a Democratic United States senator from South Carolina, who filibustered to prevent the passage of the Civil Rights Act of 1957.

While Booker did break the record for the longest speech ever made on the Senate floor — he spoke for 25 hours and 5 minutes — technically, he was not filibustering legislation. As such, this claim is mostly true.

According to the U.S. Senate, a filibuster is a term for the specific act of speaking on the Senate floor in order to delay or prevent a vote from taking place for a piece of legislation. 

Thurmond, according to the Senate website, spoke for 24 hours and 18 minutes in a filibuster of the 1957 Civil Rights Act — part of landmark legislation intended to protect the civil rights of all citizens and end segregation. The act established a Civil Rights Division in the Department of Justice,  empowered a temporary Commission on Civil Rights and gave the attorney general power to investigate and prosecute voting rights infringements.

Opposing the legislation, Thurmond began his marathon filibuster by calling the bill "unnecessary" arguing that states had already enacted legislation making it unlawful to intimidate or hinder a voter in exercising his voting rights. He went on to catalog all the laws in various states. The full text of his filibuster can be found here. 

Despite Thurmond's efforts, the bill passed hours after his speech.

After finishing his 25-hour, 5-minute speech, Booker, who is Black, said on MSNBC: "To be candid, Strom Thurmond's record always kind of … really irked me, that he would be the longest speech — that the longest speech, on our great Senate floor, was someone who was trying to stop people like me from being in the Senate."

Booker was not speaking to delay or oppose a particular bill, as a filibuster requires. His stated intention was to disrupt "business as usual" on the Senate floor and express Democratic opposition to Trump, expressing concern about the federal government's budget cuts on education, medical research, social security, health care and more. Per his website, his opening remarks were as follows:

I rise tonight with the intention of disrupting the normal business of the United States Senate for as long as I am physically able. […] These are not normal times in our nation. And they should not be treated as such in the United States Senate. The threats to the American people and American democracy are grave and urgent and we all must do more to stand against them.

Booker also referenced the late civil rights leader Rep. John Lewis:

You think we got civil rights one day because Strom Thurmond — after filibustering for 24 hours — you think we got civil rights because he came to the floor one day and said, "I've seen the light." No, we got civil rights because people marched for it, sweat for it and John Lewis bled for it.

[…]

To hate him [Thurmond] is wrong, and maybe my ego got too caught up in if I stood here maybe, maybe — just maybe — I could break this record of the man who tried to stop the rights upon which I stand. […] I'm not here, though, because of his speech. I'm here despite his speech. I'm here because as powerful as he was, the people were more powerful.

Booker ended his speech by referencing Lewis again, and calling on people to oppose the current administration's policies and cause "good trouble":

It is time to heed the words of the man I began this whole thing with: John Lewis. I beg folks to take his example of his early days where he made himself determined to show his love for his country at a time the country didn't love him. To love this country so much, to be such a patriot that he endured beatings savagely on the Edmund Pettus bridge, at lunch counters, on Freedom Rides, he said he had to do something. He would not normalize a moment like this. He would not just go along with business as usual. He wouldn't know how to solve it but there's one thing that he would do that I hope we all can do, that I think I did a little bit of tonight. He said for us to go out and cause some good trouble. Necessary trouble to redeem the soul of our nation. I want you to redeem the dream. Let's be bold in America, not demean and degrade Americans. Not divide us against each other. […] This is a moral moment. It's not left or right, it's right or wrong. Let's get in good trouble. My friends, Madame President, I yield the floor.

Highlights of Booker's speech can be viewed here:

Thurmond made it through his speech by reportedly taking long steam baths ahead of time to dry himself out so he would not urinate. Booker, meanwhile, said he hadn't eaten for days and stopped drinking fluids the night before his speech.