In 2003, Blanco was the first woman elected governor of Louisiana. Just 20 months into her term, she faced the onslaught of Hurricane Katrina and later Rita, which left more than 1,500 people dead and damaged hundreds of thousands of homes.
She did not seek reelection.
After leaving office, she announced in 2007 that she was dealing with a rare type of cancer, The Advocate reported.
"Kathleen loved this state and our people and was a shining example of what can be accomplished by hard work and determination. She led Louisiana through one of our darkest hours, when hurricanes and the failure of the federal levee system devastated much of our state," current Gov. John Bel Edwards said in a statement. "Serving as this state's first female governor, Kathleen was a trailblazer and broke many barriers, leading the way for others to follow. She stands among the giants who have helped shaped Louisiana's history."