One of his most frequently used phrases is, "My mother has a saying…" and he often would regale campaign audiences, politicians and reporters with anecdotes of his childhood and upbringing in Scranton, and later in Wilmington.
His favorite quote? "'God love him,' as my mother would say," Biden loved to recall.
In his remarks accepting the vice presidential nomination at the Democratic National Convention last August, Biden spoke emotionally about the influence his mother had on his life and the lessons she taught him.
"I thank God and I'm grateful that my mom, Catherine Eugenia Finnegan Biden, is here tonight," Biden said. "Mom, I love you."
"My mom taught her children, all the children who flocked to our house, that you're defined by your sense of honor and you're redeemed by your loyalty," he said. "Failure at some point in your life is inevitable, but giving up is unforgivable."
Biden said that his mother had such a large role in his life that she even thought she would be useful during the daily grind of the presidential campaign in the fall of 2008.
Biden joked on the trail in September of that year that his mother asked him if he was sure he didn't need her to travel on his campaign plane.
"And I said, 'Mom, I can make it'" then-Sen. Biden said to laughter. But his mother insisted – "'Do you want me to come with you, honey?'' Biden said she said.
Perhaps he could have used her when the rhetoric grew heated. Biden has described his mother as his fiercest defender, in life and in the rough and tumble political arena.
"'Show me the guy that says something about you, Joey," he said his mother said.
Biden, who had a stuttering problem as a child, spoke of how his mother tried to comfort him when he struggled to get his words out.
"She lovingly would look at me and tell me, 'Joey, it's because you're so bright, you can't get the thoughts out quickly enough,'" he said.
In his autobiography, "Promises to Keep," he described a time when his mother marched down to his catholic grammar school to confront a nun who had mocked his stuttering.
"My mother, who was so timid, so respectful of the church, stood up, walked over in front of the nun, and said, 'If you ever speak to my son like that again, I'll come back and rip that bonnet off your head. Do you understand me?'" he wrote.
Biden said his mother could not stand meanness and bullies were at the top of her list.
"When I got knocked down by guys bigger than me, and this is the God's truth, she sent me back out and said, 'Bloody their nose…so you can walk down the street the next day,' he recounted in his convention in Denver. "And that's what I did."
Even though he frequently spoke of his mother's toughness and grit, he also spoke of her softer side.
On St. Patrick's Day last year he said his mother was "the soul, spirit and essence of what it means to be an Irish American."
"She's spiritual, she's romantic, she honors tradition and she understands that the thickest of all substances is blood, and the greatest of all virtues is courage," he said.
After her fall and hospitalization last March, President Obama called Mrs. Biden "a sweetheart."