"In her lifetime of public service and unwavering commitment to working families, Congresswoman Slaughter embodied the very best of the American spirit.", House Minority Leader Nancy Pelosi (D-Calif.) said in a statement.
Slaughter was serving her 16th term in Congress and was the top Democrat on the House Rules Committee.
Slaughter, the ranking member on the House Rules Committee, reportedly suffered a "fall" last week and suffered a concussion which caused her to be hospitalized at the George Washington University in Washington, DC.
Her progressive legacy in Congress ranges from landmark government ethics legislation to health care and historic legislation to prevent discrimination. Louise was a fearless leader, deeply committed to her constituents, and a dear friend. "Congresswoman Slaughter was proud to be a strong champion for the LGBTQ community and was one of the earliest Members of Congress to support marriage equality".
Among her greatest achievements was helping shepherd the passage of the Affordable Care Act in 2010, during which she said she received a death threat and her district office window was smashed with a rock.
"For 25 years, the Office of Research on Women's Health (ORWH) has improved the lives of women across the country and improved the way our nation conducts biomedical research", she said when marking the 25th anniversary of the office in 2015.
After marrying Robert Slaughter in 1957, the couple moved to the Rochester area where she began to get involved in local politics.
Speculation - driven by younger members expressing a desire for change - also continues about the future of Pelosi, 77, and her leadership team of Reps.
They married in 1957, and he died in 2014. Her efforts to fix the medical research imbalance that emphasized clinical trials on diseases that affect white men rather than those that hit women and minorities disproportionately led to the NIH Revitalization Act of 1993. She was elected to the New York State Assembly in 1984, serving two terms. She once called the arts "the only thing that I know that tells us who we were and who we are and who we hope to be".
Together the couple had three daughters and seven grandchildren. She also helped write the Violence Against Women Act and a 2008 law created to protect people with genetic predispositions to health conditions from facing discrimination from their employers or health insurance companies. Redistricting in 2012 dramatically altered Slaughter's district, fueling speculation that she might retire. The ferocity of her advocacy was matched only by the depth of her compassion and humanity.