Democratic Rep. Sheila Jackson Lee of Texas has died, her office announced Friday evening. She was 74 years old.

A cause of death was not immediately disclosed. Last month, however, Jackson Lee revealed that she had been diagnosed with pancreatic cancer.

"A fierce champion of the people, she was affectionately and simply known as 'Congresswoman' by her constituents in recognition of her near-ubiquitous presence and service to their daily lives for more than 30 years," her office said in a statement.

Jackson Lee, who represented the 18th Congressional District, was "a towering figure in our politics," President Biden said in a statement Saturday.

"Always fearless, she spoke truth to power and represented the power of the people of her district in Houston with dignity and grace," he said.

The president said Jackson Lee's spirit was unbreakable.

"I had the honor of working with her during her nearly 30 years in Congress," Mr. Biden said. "No matter the issue — from delivering racial justice to building an economy for working people — she was unrelenting in her leadership."

She was born in Queens, New York, graduated from Yale University in 1972 and received her law degree from the University of Virginia Law School. She was a municipal judge before beginning her political career as a member of the Houston City Council in the late 1980s, then made the jump to Congress in 1995. She lost a closely-watched Houston mayoral race last December. 

In a statement, the Congressional Black Caucus praised Jackson Lee as a "titan and stalwart" who was a "fierce advocate for social and economic justice, national and homeland security, energy independence, and children and working families."

Jackson Lee was the lead sponsor of legislation signed into law by Mr. Biden in June 2021 to make Juneteenth a federal holiday. 

"The potential of having this national holiday opens a whole world of discussion for America, a whole reckoning with racism and the systemic racism that permeates the nation," she told CBS Mornings in a June 2020 interview.  

"Known for proudly wearing her braided crown, Congresswoman Jackson Lee fought every day for the least, the lost and the left behind, and was a warrior for racial and economic justice," House Minority Leader Hakeem Jeffries said in a statement late Friday, noting that Jackson Lee was also the first woman to ever serve as chair of the House Judiciary Committee's crime subcommittee. 

In confirming her pancreatic cancer diagnosis last month, Jackson Lee said that she was "undergoing treatment to battle this disease that impacts tens of thousands of Americans every year."

Back in 2012, Jackson Lee revealed that she had undergone treatment for breast cancer and made a full recovery. She then worked in Congress to secure millions of dollars in funding for breast cancer research.

"This is a tremendous loss," Sen. Majority Leader Chuck Schumer said in a social media post Friday of her passing. "Rep. Sheila Jackson Lee fought so hard throughout her life to make our country a better place for all. May her memory be a blessing."

Republican Texas Gov. Greg Abbott said he and his wife Cecilia will always remember Jackson Lee, calling her a "tireless advocate for the people of Houston."

"Her legacy of public service and dedication to Texas will live on," he said.

She is survived by her husband and two children. 

— Jordan Freiman contributed to this report. 

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• Texas
• Obituary

Faris Tanyos

Faris Tanyos is a news editor for CBSNews.com, where he writes and edits stories and tracks breaking news. He previously worked as a digital news producer at several local news stations up and down the West Coast.