Opal Lee, described as the "grandmother of the movement”, said that as the 250th birthday of America approaches, people should also remember Juneteenth.“We celebrate 160 years of freedom for the enslaved human beings who weren't even considered people when the Declaration of Independence was signed,” Lee said in a statement obtained by ABC News.Juneteenth -- also known as Freedom Day, Liberation Day and Emancipation Day -- is celebrated on June 19 to mark the day in 1865 when African American slaves in Galveston, Texas, were among the last to be told they had been freed -- a full two-and-a-half years after the Emancipation Proclamation outlawed slavery in the Confederacy and two months after the Civil War officially ended.Vice President Kamala Harris watches as Opal Lee (2nd L), the activist known as the grandmother of Juneteenth, is given a pen after President Joe Biden signs the Juneteenth National Independence Day Act, in the East Room of the White House, June 17, 2021.Jim Watson/AFP via Getty ImagesIn November of 2025, the Department of the Interior announced in a news release that it would no longer allow free entrance into national parks on Juneteenth and Martin Luther King Jr. Day for 2026. Instead, they would allow free entrance on President Donald Trump’s birthday, June 14, which also falls on Flag Day.ABC News reached out to the Interior Department asking the reason why Juneteenth and MLK Day were removed as fee-free days at national parks for 2026. The department referred us back to the press release. The release does not refer to either holiday. They were simply removed from the list of fee-free holidays at national parks.Dr. Opal Lee attends the National Women's History Museum Women Making History Awards at The Anthem on March 20, 2025 in Washington, D.C.Shannon Finney/Getty ImagesThe Interior Department has also made several changes to national parks across the country. A coalition of organizations filed a lawsuit challenging the administration's removal of materials, markers and exhibits that cover issues related to diverse communities, oppression committed by the United States throughout its history, as well as issues related to science and the environment, including climate change.“As efforts seem to be increasing to erase that (Black) history, it's even more important that we don't forget,” Lee said in her statement obtained by ABC News. “I don't care what your background is or what you look like. If you cherish liberty, Juneteenth is a holiday for you.”In 2016, at 89 years old, Lee, a former teacher and lifelong activist, walked from her home in Fort Worth, Texas, to the nation's capital in an effort to get Juneteenth -- commemorating the end of slavery in the United States -- named a national holiday.Four years later, Lee's activism helped push Congress to establish a new national holiday for the first time in nearly 40 years.President Joe Biden is applauded as he reaches for a pen to sign the Juneteenth National Independence Day Act into law as Vice President Kamala Harris stands by in the East Room of the White House June 17, 2021.Carlos Barria/ReutersWhen then-President Joe Biden signed a bill in 2021 making Juneteenth a federal holiday, it became the first federal holiday established in the United States since Martin Luther King Jr. Day was signed into law in 1983.In 2026, Lee, now 99 and recovering from an illness, says she will likely ride in a car towards the front of the annual Walk for Freedom event in Fort Worth on Friday, if she is feeling well.Popular Reads“Don't just walk for yourself, walk for your family, walk for your community, walk for the ancestors who dreamed of this kind of freedom, and walk for the work that still has to be done,” Lee said in a statement obtained by ABC News, regarding the annual walk.In 2024 -- the same year she was awarded the Presidential Medal of Freedom -- Lee marked the anniversary at the White House's first-ever Juneteenth celebration, a concert that featured Jennifer Hudson and Audra McDonald.A Texas native, Lee said she experienced racial unrest firsthand during her childhood, including the night hundreds of rioters set fire to her family's home on June 19, 1939.Opal Lee, 93, stands in front of the East Annie Street lot on June 2, 2021, where white rioters attacked, invaded and burned her family's home in 1939.Amanda McCoy/Fort Worth Star-Telegram/TNS via Getty ImagesLee remembers her parents sending her to a friend’s house several blocks away when an angry mob showed up at her family’s home to protest Black residents moving into the Fort Worth neighborhood. Lee was 12 years old.“It amazes me because we would have been good neighbors, you know,” Lee told GMA3 in June 2024.Advocates like Lee say Juneteenth offers a day to reflect on slavery's terrible stain on American history and for celebrations that look similar to those on the Fourth of July.Juneteenth celebrations have become more mainstream in recent years, taking on added significance in 2020 when the country went through a racial reckoning after the murder of George Floyd.“As long as I have breath, I'll shout that none of us are free until we are all free,” Lee said in a statement obtained by ABC News. “So, let's celebrate freedom from Juneteenth to the 4th of July.”ABC News’ Deena Zaru contributed to this report.