President Biden will establish a national monument Tuesday to honor Emmett Till, the black teenager who was kidnapped and murdered by white supremacists in 1955, and his mother, Mamie Till-Mobley, who helped galvanize the civil rights movement by bravely putting her son’s brutalized body on display for the world to see.

The Emmett Till and Mamie Till-Mobley National Monument will encompass three protected sites in Illinois, where Emmett was born 82 years ago, and in Mississippi, where he was murdered at age 14 after being accused of whistling at a white woman.

The president’s decision to dedicate a monument to two figures whose stories underscore the legacy of racism in America comes amid a divisive political battle over how to teach black history in schools.

Last week, Florida Gov. Ron DeSantis, who is campaigning for the Republican presidential nomination, came under fire after his state’s education officials introduced new standards for teaching black history.

The standards say high school students must be taught that “slaves developed skills that, in some cases, could be applied to their personal benefit.” The description drew a widespread rebuke, including from Vice President Kamala Harris.

“They insult us in an attempt to mislead us and we will not stand for it,” Harris said last week during a speech in Indianapolis.

Mr. DeSantis, who has made fighting a “wake-up” agenda in education a distinctive part of his electoral platform, defended the standards, which were created to comply with a law he signed known as “stop the WOKE law.” He accused Democrats of “indoctrinating students.”

Since Biden took office, more than 40 states have introduced or passed laws or taken other steps to restrict how race and racism are taught. according to Education Week. The outlet has been tracking legislation against so-called “critical race theory,” a term that has been adopted by conservative activists as a mixed bag for teachings on race.

Karine Jean-Pierre, the White House press secretary, referenced Florida’s new standards Monday, saying the Till monument came “at an important time.”

“Let us not forget what we have seen in recent months as we have witnessed extremist officials in Florida and across the country lie about American history; the most recent example shamefully, shamefully promotes a lie that enslaved people actually benefited from slavery,” he said. “It is inaccurate, insulting. It is hurtful and prevents an honest telling of our nation’s history.”

The Biden administration has invoked Emmett’s death and Ms. Till-Mobley’s activism before. During a White House screening of the film “Till” in February, Biden told the crowd that he chose the film because “history matters.”

“Remembering history is shedding light on the good, the bad, the truth and who we are as a nation,” he said at the screening. “And our history shows that while darkness and denialism hide a lot, they erase nothing. They can’t erase the past, and they shouldn’t.”

He also said that signing the Emmett Till Anti-Lynching Act, which made lynching a federal hate crime, in March 2022, was “one of the great honors of my career.” Mr. Biden also signed a bill passed by the House of Representatives that would posthumously award Emmett and Ms. Till-Mobley the Congressional Gold Medal, the body’s highest civilian honor.

The monument locations are intended to honor the Till family.

One site is Graball Landing in Tallahatchie County, Mississippi, where Emmett’s body is believed to have been pulled from the Tallahatchie River. His body was so disfigured that it was identifiable only by a ring his mother had given him before he left to visit relatives in Mississippi.

Another is the church in Chicago where Emmett’s funeral was held, Roberts Temple Church of God in Christ. Ms Till-Mobley insisted on an open casket, saying “the whole nation had to bear witness to this.”

More than 100,000 people entered the church during the days of public visits.

The third site is the Tallahatchie County Second District Courthouse in Sumner, Mississippi, where an all-white jury acquitted Emmett’s killers.

Ana Betts in New York and Zolan Kanno Youngs in Washington contributed reporting.