The younger Biden had been the attorney general of Delaware for several years, and had planned a 2016 gubernatorial run. He recovered from a mild stroke in 2010.
A statement from the Vice President Biden read:
"It is with broken hearts that Hallie, Hunter, Ashley, Jill and I announce the passing of our husband, brother and son, Beau, after he battled brain cancer with the same integrity, courage and strength he demonstrated every day of his life.
"The entire Biden family is saddened beyond words. We know that Beau's spirit will live on in all of us-especially through his brave wife, Hallie, and two remarkable children, Natalie and Hunter.
"Beau's life was defined by service to others. As a young lawyer, he worked to establish the rule of law in war-torn Kosovo. A major in the Delaware National Guard, he was an Iraq War veteran and was awarded the Bronze Star. As Delaware's Attorney General, he fought for the powerless and made it his mission to protect children from abuse.
"More than his professional accomplishments, Beau measured himself as a husband, father, son and brother. His absolute honor made him a role model for our family. Beau embodied my father's saying that a parent knows success when his child turns out better than he did.
"In the words of the Biden family: Beau Biden was, quite simply, the finest man any of us have ever known."
President Obama issued a brief statement that read: "Michelle and I humbly pray for the good Lord to watch over Beau Biden, and to protect and comfort his family here on Earth."